21 CFR 556.70 - Bacitracin.

Code of Federal Regulations, 2014 CFR

2014-04-01

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.70 Bacitracin. (a) Acceptable daily intake (ADI). The ADI for total...

21 CFR 556.70 - Bacitracin.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Bacitracin. 556.70 Section 556.70 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for...

21 CFR 556.70 - Bacitracin.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Bacitracin. 556.70 Section 556.70 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for...

Biofunctionalization of titanium with bacitracin immobilization shows potential for anti-bacteria, osteogenesis and reduction of macrophage inflammation.

PubMed

Nie, Bin'en; Ao, Haiyong; Zhou, Jianliang; Tang, Tingting; Yue, Bing

2016-09-01

Titanium has been widely used in the orthopedic and dental fields, however, the inert nature of Ti makes it unsuitable for application in promoting bone cell growth，osteogenic differentiation and antibacterial ability. The aims of the current study were to investigate the antimicrobial activity and biofunction of the polypeptide antibiotic bacitracin, and obtain a multi-biofunctional titanium implant by covalently-immobilizing titanium with the bacitracin. The results showed that the bacitracin possessed low minimum inhibitory concentration (MIC) to both Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus (MRSA), with the non-cytotoxicity concentration up to 500μg/mL to human bone marrow mesenchymal stem cells (hBMSCs), furthermore, the bacitracin could improve the osteogenic differentiation of hBMSCs. The results of Scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) indicated that bacitracin had been covalently immobilized on the surface of titanium. Immobilized bacitracin could improve the hydrophilic of immobilized titanium. The results of antimicrobial assay demonstrated that the covalently-immobilized bacitracin also had excellent antimicrobial property, and the bacitracin immobilized titanium could inhibit bacterial adhesion and colonization. The results of cell biology experiments proved that the bacitracin immobilized titanium could improve hBMSCs' adhesion, proliferation and osteogenic differentiation. We also found that the macrophages were difficult to spread or activate on the surface of bacitracin immobilized titanium, and the secretion of inflammatory factors had been inhibited. In conclusion, the novel bacitracin immobilized titanium has multi-biofunctions including outstanding antibacterial properties, excellent cell biology performance, and restraining inflammation, which has exciting application prospect. Copyright © 2016 Elsevier B.V. All rights reserved.

Immediate and heterogeneous response of the LiaFSR two-component system of Bacillus subtilis to the peptide antibiotic bacitracin.

PubMed

Kesel, Sara; Mader, Andreas; Höfler, Carolin; Mascher, Thorsten; Leisner, Madeleine

2013-01-01

Two-component signal transduction systems are one means of bacteria to respond to external stimuli. The LiaFSR two-component system of Bacillus subtilis consists of a regular two-component system LiaRS comprising the core Histidine Kinase (HK) LiaS and the Response Regulator (RR) LiaR and additionally the accessory protein LiaF, which acts as a negative regulator of LiaRS-dependent signal transduction. The complete LiaFSR system was shown to respond to various peptide antibiotics interfering with cell wall biosynthesis, including bacitracin. Here we study the response of the LiaFSR system to various concentrations of the peptide antibiotic bacitracin. Using quantitative fluorescence microscopy, we performed a whole population study analyzed on the single cell level. We investigated switching from the non-induced 'OFF' state into the bacitracin-induced 'ON' state by monitoring gene expression of a fluorescent reporter from the RR-regulated liaI promoter. We found that switching into the 'ON' state occurred within less than 20 min in a well-defined switching window, independent of the bacitracin concentration. The switching rate and the basal expression rate decreased at low bacitracin concentrations, establishing clear heterogeneity 60 min after bacitracin induction. Finally, we performed time-lapse microscopy of single cells confirming the quantitative response as obtained in the whole population analysis for high bacitracin concentrations. The LiaFSR system exhibits an immediate, heterogeneous and graded response to the inducer bacitracin in the exponential growth phase.

Immediate and Heterogeneous Response of the LiaFSR Two-Component System of Bacillus subtilis to the Peptide Antibiotic Bacitracin

PubMed Central

Kesel, Sara; Mader, Andreas; Höfler, Carolin; Mascher, Thorsten; Leisner, Madeleine

2013-01-01

Background Two-component signal transduction systems are one means of bacteria to respond to external stimuli. The LiaFSR two-component system of Bacillus subtilis consists of a regular two-component system LiaRS comprising the core Histidine Kinase (HK) LiaS and the Response Regulator (RR) LiaR and additionally the accessory protein LiaF, which acts as a negative regulator of LiaRS-dependent signal transduction. The complete LiaFSR system was shown to respond to various peptide antibiotics interfering with cell wall biosynthesis, including bacitracin. Methodology and Principal Findings Here we study the response of the LiaFSR system to various concentrations of the peptide antibiotic bacitracin. Using quantitative fluorescence microscopy, we performed a whole population study analyzed on the single cell level. We investigated switching from the non-induced ‘OFF’ state into the bacitracin-induced ‘ON’ state by monitoring gene expression of a fluorescent reporter from the RR-regulated liaI promoter. We found that switching into the ‘ON’ state occurred within less than 20 min in a well-defined switching window, independent of the bacitracin concentration. The switching rate and the basal expression rate decreased at low bacitracin concentrations, establishing clear heterogeneity 60 min after bacitracin induction. Finally, we performed time-lapse microscopy of single cells confirming the quantitative response as obtained in the whole population analysis for high bacitracin concentrations. Conclusion The LiaFSR system exhibits an immediate, heterogeneous and graded response to the inducer bacitracin in the exponential growth phase. PMID:23326432

Tannins and Bacitracin Differentially Modulate Gut Microbiota of Broiler Chickens

PubMed Central

Pin Viso, Natalia Daniela; Farber, Marisa Diana

2018-01-01

Antibiotic growth promoters have been used for decades in poultry farming as a tool to maintain bird health and improve growth performance. Global concern about the recurrent emergence and spreading of antimicrobial resistance is challenging the livestock producers to search for alternatives to feed added antibiotics. The use of phytogenic compounds appears as a feasible option due to their ability to emulate the bioactive properties of antibiotics. However, detailed description about the effects of in-feed antibiotics and alternative natural products on chicken intestinal microbiota is lacking. High-throughput sequencing of 16S rRNA gene was used to study composition of cecal microbiota in broiler chickens supplemented with either bacitracin or a blend of chestnut and quebracho tannins over a 30-day grow-out period. Both tannins and bacitracin had a significant impact on diversity of cecal microbiota. Bacitracin consistently decreased Bifidobacterium while other bacterial groups were affected only at certain times. Tannins-fed chickens showed a drastic decrease in genus Bacteroides while certain members of order Clostridiales mainly belonging to the families Ruminococcaceae and Lachnospiraceae were increased. Different members of these groups have been associated with an improvement of intestinal health and feed efficiency in poultry, suggesting that these bacteria could be associated with productive performance of birds. PMID:29682522

21 CFR 520.154a - Soluble bacitracin methylene disalicylate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Soluble bacitracin methylene disalicylate. 520.154a Section 520.154a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.154a...

21 CFR 520.154a - Soluble bacitracin methylene disalicylate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Soluble bacitracin methylene disalicylate. 520.154a Section 520.154a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.154a...

Antimicrobial Susceptibility of Bacillus Strains Isolated from Primary Starters for African Traditional Bread Production and Characterization of the Bacitracin Operon and Bacitracin Biosynthesis

PubMed Central

Sørensen, Kim I.; Thorsen, Line; Stuer-Lauridsen, Birgitte; Abdelgadir, Warda S.; Nielsen, Dennis S.; Derkx, Patrick M. F.; Jespersen, Lene

2012-01-01

Bacillus spp. are widely used as feed additives and probiotics. However, there is limited information on their resistance to various antibiotics, and there is a growing concern over the transfer of antibiotic resistance genes. The MIC for 8 antibiotics was determined for 85 Bacillus species strains, Bacillus subtilis subsp. subtilis (n = 29), Bacillus licheniformis (n = 38), and Bacillus sonorensis (n = 18), all of which were isolated from starters for Sudanese bread production. All the strains were sensitive to tetracycline (8.0 mg/liter), vancomycin (4.0 mg/liter), and gentamicin (4.0 mg/liter) but resistant to streptomycin. Sensitivity to clindamycin, chloramphenicol, and kanamycin was species specific. The erythromycin resistance genes ermD and ermK were detected by PCR in all of the erythromycin-resistant (MIC, ≥16.0 mg/liter) B. licheniformis strains and one erythromycin-sensitive (MIC, 4.0 mg/liter) B. licheniformis strain. Several amino acid changes were present in the translated ermD and ermK nucleotide sequences of the erythromycin-sensitive strain, which could indicate ErmD and ErmK protein functionalities different from those of the resistance strains. The ermD and ermK genes were localized on an 11.4-kbp plasmid. All of the B. sonorensis strains harbored the bacitracin synthetase gene, bacA, and the transporter gene bcrA, which correlated with their observed resistance to bacitracin. Bacitracin was produced by all the investigated species strains (28%), as determined by ultra-high-definition quadrupole time-of-flight liquid chromatography-mass spectrometry (UHD-QTOF LC/MS). The present study has revealed species-specific variations in the antimicrobial susceptibilities of Bacillus spp. and provides new information on MIC values, as well as the occurrence of resistance genes in Bacillus spp., including the newly described species B. sonorensis. PMID:22941078

Antimicrobial susceptibility of Bacillus strains isolated from primary starters for African traditional bread production and characterization of the bacitracin operon and bacitracin biosynthesis.

PubMed

Adimpong, David B; Sørensen, Kim I; Thorsen, Line; Stuer-Lauridsen, Birgitte; Abdelgadir, Warda S; Nielsen, Dennis S; Derkx, Patrick M F; Jespersen, Lene

2012-11-01

Bacillus spp. are widely used as feed additives and probiotics. However, there is limited information on their resistance to various antibiotics, and there is a growing concern over the transfer of antibiotic resistance genes. The MIC for 8 antibiotics was determined for 85 Bacillus species strains, Bacillus subtilis subsp. subtilis (n = 29), Bacillus licheniformis (n = 38), and Bacillus sonorensis (n = 18), all of which were isolated from starters for Sudanese bread production. All the strains were sensitive to tetracycline (8.0 mg/liter), vancomycin (4.0 mg/liter), and gentamicin (4.0 mg/liter) but resistant to streptomycin. Sensitivity to clindamycin, chloramphenicol, and kanamycin was species specific. The erythromycin resistance genes ermD and ermK were detected by PCR in all of the erythromycin-resistant (MIC, ≥16.0 mg/liter) B. licheniformis strains and one erythromycin-sensitive (MIC, 4.0 mg/liter) B. licheniformis strain. Several amino acid changes were present in the translated ermD and ermK nucleotide sequences of the erythromycin-sensitive strain, which could indicate ErmD and ErmK protein functionalities different from those of the resistance strains. The ermD and ermK genes were localized on an 11.4-kbp plasmid. All of the B. sonorensis strains harbored the bacitracin synthetase gene, bacA, and the transporter gene bcrA, which correlated with their observed resistance to bacitracin. Bacitracin was produced by all the investigated species strains (28%), as determined by ultra-high-definition quadrupole time-of-flight liquid chromatography-mass spectrometry (UHD-QTOF LC/MS). The present study has revealed species-specific variations in the antimicrobial susceptibilities of Bacillus spp. and provides new information on MIC values, as well as the occurrence of resistance genes in Bacillus spp., including the newly described species B. sonorensis.

The effect of inhibitors of endogenous opioid degradation, bacitracin, bestatin, captopril, and D-phenylalanine, on digoxin-induced arrhythmias in guinea pigs.

PubMed

Rabkin, S W; Redston, M

1989-08-01

The purpose of this study was to investigate the effect of inhibition of endogenous opioid degradation on digitalis-induced arrhythmias, utilizing the inhibitors bacitracin, bestatin, captopril, and D-phenylalanine. Guinea pigs, anesthetized with pentobarbital, 50 mg/kg i.p., and breathing spontaneously received intracerebroventricular (i.c.v.) injection of bacitracin (6.8 mg/kg), bestatin (1 mg/kg), captopril (2 mg/kg), D-phenylalanine (1.2 mg/kg) or the diluent, saline. Digitalis arrhythmias were induced by a 50 micrograms/kg i.v. bolus of digoxin followed by 500 micrograms.kg-1.h-1 i.v. Bacitracin and bestatin, but not captopril or D-phenylalanine, significantly (p less than 0.05) altered the relationship between the digoxin dose and the first occurrence of arrhythmias, i.e., digoxin-induced ventricular arrhythmias became manifest at lower digoxin doses. The mean digoxin dose and ED50s, at which arrhythmias first occurred, were significantly (p less than 0.05) reduced by bacitracin and bestatin. The findings were similar for fatal arrhythmias, although D-phenylalanine appeared to decrease the digoxin dose at the development of fatal arrhythmias. The opioid antagonist naloxone, in a 50 micrograms/kg bolus and 50 micrograms.kg-1.h-1 i.c.v., completely prevented these effects of bacitracin and reduced the effect of bestatin. The relationship to arrhythmias could not be ascribed to an effect on blood pressure, as the blood pressure response to digoxin was the same in bestatin, D-phenylalanine, and control groups. To examine whether systemic administration of an inhibitor of opioid degradation had similar effects, a second protocol was selected with systemic administration of bacitracin because it altered the dose effect relationship after i.c.v. administration and systemic concentrations could be readily attained. Bacitracin, in a 13.5 mg/kg i.v. bolus and 135 mg.kg-1.h-1 i.v., was followed by 100 micrograms/kg digoxin i.v. every 15 min.(ABSTRACT TRUNCATED AT 250

Spectrophotometric determination of bacitracin in bulk drug as dabsyl derivative in a range of visible light.

PubMed

Krzek, Jan; Piotrowska, Joanna

2011-01-01

A fast spectrophotometric method has been developed for bacitracin identification and determination after condensation reaction with dabsyl chloride. In addition, determination of dye stability of sulfonamide derivative and identification of the molar ratio of reagents was done at various time-points. The developed method has a good linearity with very broad spectrum, correlation coefficient of r = 0.9972, good precision (RSD = 1.54 +/- 0.11%), and recovery at three different levels of concentration was found between 98.33% and 103.47%. Usefulness of the method was demonstrated by positive results obtained during determination of bacitracin concentration in bulk drug.

Application of Oxygen-Enriched Aeration in the Production of Bacitracin by Bacillus licheniformis

PubMed Central

Flickinger, M. C.; Perlman, D.

1979-01-01

The physiological effects of controlling the dissolved oxygen tension at 0.01, 0.02, and 0.05 atm by the use of oxygen-enriched aeration were investigated during growth and bacitracin production by Bacillus licheniformis ATCC 10716. Up to a 2.35-fold increase in the final antibiotic yield and a 4-fold increase in the rate of bacitracin synthesis were observed in response to O2-enriched aeration. The increase in antibiotic production was accompanied by increased respiratory activity and an increase in the specific productivity of the culture from 1.3 to 3.6 g of antibiotic per g of cell mass produced. Oxygen enrichment of the aeration decreased medium carbohydrate uptake and the maximum specific growth rate of B. licheniformis from 0.6 h−1 to as low as 0.15 h−1, depending upon the level of enrichment and the conditions of oxygen transfer rate (impeller speed). The response of this culture to O2 enrichment suggests that this method of controlling the dissolved oxygen tension for antibiotic-producing cultures may simulate conditions that would occur if the carbon source were fed slowly, as is often employed to optimize antibiotic production. Analysis of the biologically active bacitracins produced by B. licheniformis ATCC 10716 suggested that the ratio of biologically active peptides was not changed by O2 enrichment, nor were any new biologically active compounds formed. Images PMID:34361

21 CFR 524.155 - Bacitracin, neomycin, polymyxin B, and hydrocortisone ophthalmic ointment.

Code of Federal Regulations, 2014 CFR

2014-04-01

... hydrocortisone ophthalmic ointment. 524.155 Section 524.155 Food and Drugs FOOD AND DRUG ADMINISTRATION... TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.155 Bacitracin, neomycin, polymyxin B, and hydrocortisone... sulfate, and10 mg of hydrocortisone. (b) Sponsors. See Nos. 000061 and 043264 in § 510.600(c) of this...

Facile synthesis of bacitracin-templated palladium nanoparticles with superior electrocatalytic activity

NASA Astrophysics Data System (ADS)

Li, Yanji; Wang, Zi; Li, Xiaoling; Yin, Tian; Bian, Kexin; Gao, Faming; Gao, Dawei

2017-02-01

Palladium nanomaterials have attracted great attention on the development of electrocatalysts for fuel cells. Herein, we depicted a novel strategy in the synthesis of palladium nanoparticles with superior electrocatalytic activity. The new approach, based on the self-assembly of bacitracin biotemplate and palladium salt for the preparation of bacitracin-palladium nanoparticles (Bac-PdNPs), was simple, low-cost, and green. The complex, composed by a series of spherical Bac-PdNPs with a diameter of 70 nm, exhibited a chain-liked morphology in TEM and a face-centered cubic crystal structure in X-Ray diffraction and selected area electron diffraction. The palladium nanoparticles were mono-dispersed and stable in aqueous solution as shown in TEM and zeta potential. Most importantly, compared to the commercial palladium on carbon (Pd/C) catalyst (8.02 m2 g-1), the Bac-PdNPs showed a larger electrochemically active surface area (47.57 m2 g-1), which endowed the products an excellent electrocatalytic activity for ethanol oxidation in alkaline medium. The strategy in synthesis of Bac-PdNPs via biotemplate approach might light up new ideas in anode catalysts for direct ethanol fuel cells.

Understanding the mechanisms of zinc bacitracin and avilamycin on animal production: linking gut microbiota and growth performance in chickens.

PubMed

Crisol-Martínez, Eduardo; Stanley, Dragana; Geier, Mark S; Hughes, Robert J; Moore, Robert J

2017-06-01

Unravelling the mechanisms of how antibiotics influence growth performance through changes in gut microbiota can lead to the identification of highly productive microbiota in animal production. Here we investigated the effect of zinc bacitracin and avilamycin on growth performance and caecal microbiota in chickens and analysed associations between individual bacteria and growth performance. Two trials were undertaken; each used 96 individually caged 15-day-old Cobb broilers. Trial 1 had a control group (n = 48) and a zinc bacitracin (50 ppm) treatment group (n = 48). Trial 2 had a control group (n = 48) and an avilamycin (15 ppm) treatment group (n = 48). Chicken growth performance was evaluated over a 10-day period, and caecal microbiota was characterised by sequencing of bacterial 16S rRNA gene amplicons. Avilamycin produced no effect on growth performance and exhibited little significant disturbance of the microbiota structure. However, zinc bacitracin reduced the feed conversion ratio (FCR) in treated birds, changed the composition and increased the diversity of their caecal microbiota by reducing dominant species. Avilamycin only produced minor reductions in the abundance of two microbial taxa, whereas zinc bacitracin produced relatively large shifts in a number of taxa, primarily Lactobacillus species. Also, a number of phylotypes closely related to lactobacilli species were positively or negatively correlated with FCR values, suggesting contrasting effects of Lactobacillus spp. on chicken growth performance. By harnessing such bacteria, it may be possible to develop high-productivity strategies in poultry that rely on the use of probiotics and less on in-feed antibiotics.

75 FR 7555 - New Animal Drugs for Use in Animal Feeds; Bacitracin Zinc; Nicarbazin

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-22

.... FDA-2010-N-0002] New Animal Drugs for Use in Animal Feeds; Bacitracin Zinc; Nicarbazin AGENCY: Food... amending the animal drug regulations to reflect approval of an original abbreviated new animal drug... generic copy of NADA 141-146, sponsored by Phibro Animal Health, for combination use of BACIFERM...

Self-assembly of bacitracin-gold nanoparticles and their toxicity analysis.

PubMed

Li, Xiaoling; Wang, Zi; Li, Yanji; Bian, Kexin; Yin, Tian; Gao, Dawei

2018-01-01

As the widely use of gold nanoparticles (AuNPs) in drug delivery, the precise control on the size and morphology of the AuNPs is urgently required. In this scenario, traditional synthesis methods cannot meet current requirement because of their inherent defects. We have depicted here a novel method for fabricating monodispersed large size gold nanoparticles, based on the self-assembly of bacitracin. The AuNPs could be facilely, low-cost, and green synthesized with repeatability and controllability in this method. The Bac gold nanoparticles (Bac-AuNPs), composed by bacitracin core and gold shell, exhibited a spherical morphology in TEM and a face-centered cubic crystal structure in X-Ray diffraction and selected area electron diffraction. The mean diameter of the Bac-AuNPs was 89nm. The nanoparticles were mono-dispersed and the zeta potential of the nanoparticles was 4.1±0.64mV. Notably, in cell viability assay, the Bac-AuNPs showed less toxicity to HepG2 cells and HEK293 cells compared to small size AuNPs. Collectively, the size, rheological characteristic and the biocompatibility supported the use of the gold nanoparticles as intracellular delivery vehicles for drug delivery, especially for tumor therapy. And this study could provide a maneuverable, controllable and green strategy for the synthesis of AuNPs, which would be applied in disease diagnosis and therapy with biosafety. Copyright © 2017. Published by Elsevier B.V.

21 CFR 524.155 - Bacitracin zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate...

Code of Federal Regulations, 2013 CFR

2013-04-01

... sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment. 524.155 Section 524.155 Food and... zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment... hydrocortisone. (2) To 043264; each gram of ointment contains 400 units of bacitracin zinc, 10,000 units of...

21 CFR 524.155 - Bacitracin zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate...

Code of Federal Regulations, 2010 CFR

2010-04-01

... sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment. 524.155 Section 524.155 Food and... zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment... hydrocortisone. (2) To 025463; each gram of ointment contains 400 units of bacitracin zinc, 10,000 units of...

21 CFR 524.155 - Bacitracin zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate...

Code of Federal Regulations, 2012 CFR

2012-04-01

... sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment. 524.155 Section 524.155 Food and... zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment... hydrocortisone. (2) To 025463; each gram of ointment contains 400 units of bacitracin zinc, 10,000 units of...

21 CFR 524.155 - Bacitracin zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate...

Code of Federal Regulations, 2011 CFR

2011-04-01

... sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment. 524.155 Section 524.155 Food and... zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment... hydrocortisone. (2) To 025463; each gram of ointment contains 400 units of bacitracin zinc, 10,000 units of...

Multi-year and short-term responses of soil ammonia-oxidizing prokaryotes to zinc bacitracin, monensin, and ivermectin, singly or in combination.

PubMed

Magda, Konopka; Hugh A L, Henry; Romain, Marti; Edward, Topp

2015-03-01

A field experiment was initiated whereby a series of replicated plots received annual applications of ivermectin, monensin, and zinc bacitracin, either singly or in a mixture. Pharmaceuticals were added at concentrations of 0.1 mg/kg soil or 10 mg/kg soil. The authors collected soil samples in 2013, before and after the fourth annual application of pharmaceuticals. In addition, a 30-d laboratory experiment was undertaken with the same soil and same pharmaceuticals, but at concentrations of 100 mg/kg soil. The impact of the pharmaceuticals on nitrification rates, on the abundance of ammonia-oxidizing bacteria (AOB), and on the abundance of ammonia-oxidizing archaea (AOA) was assessed. None of the pharmaceuticals at 0.1 mg/kg had any effect on nitrification. Referenced to control soil, nitrification was accelerated in soil exposed to 100 mg/kg zinc bacitracin or 10 mg/kg of the pharmaceutical mixture, but none of the treatments inhibited nitrification. Neither AOB abundance nor AOA abundance was affected by the pharmaceuticals at 0.1 mg/kg. At 10 mg/kg, monensin, zinc bacitracin, and a mixture of all 3 pharmaceuticals suppressed the abundance of AOB, and zinc bacitracin and the mixture increased AOA abundance. The decrease in AOB abundance and increase in AOA abundance when exposed to 10 mg/kg soil suggests that AOB are more sensitive to these chemicals and that AOA populations can expand to occupy the partially vacated niche. Published 2014 SETAC.

A Sensory Complex Consisting of an ATP-binding Cassette Transporter and a Two-component Regulatory System Controls Bacitracin Resistance in Bacillus subtilis*

PubMed Central

Dintner, Sebastian; Heermann, Ralf; Fang, Chong; Jung, Kirsten; Gebhard, Susanne

2014-01-01

Resistance against antimicrobial peptides in many Firmicutes bacteria is mediated by detoxification systems that are composed of a two-component regulatory system (TCS) and an ATP-binding cassette (ABC) transporter. The histidine kinases of these systems depend entirely on the transporter for sensing of antimicrobial peptides, suggesting a novel mode of signal transduction where the transporter constitutes the actual sensor. The aim of this study was to investigate the molecular mechanisms of this unusual signaling pathway in more detail, using the bacitracin resistance system BceRS-BceAB of Bacillus subtilis as an example. To analyze the proposed communication between TCS and the ABC transporter, we characterized their interactions by bacterial two-hybrid analyses and could show that the permease BceB and the histidine kinase BceS interact directly. In vitro pulldown assays confirmed this interaction, which was found to be independent of bacitracin. Because it was unknown whether BceAB-type transporters could detect their substrate peptides directly or instead recognized the peptide-target complex in the cell envelope, we next analyzed substrate binding by the transport permease, BceB. Direct and specific binding of bacitracin by BceB was demonstrated by surface plasmon resonance spectroscopy. Finally, in vitro signal transduction assays indicated that complex formation with the transporter influenced the autophosphorylation activity of the histidine kinase. Taken together, our findings clearly show the existence of a sensory complex composed of TCS and ABC transporters and provide the first functional insights into the mechanisms of stimulus perception, signal transduction, and antimicrobial resistance employed by Bce-like detoxification systems. PMID:25118291

A sensory complex consisting of an ATP-binding cassette transporter and a two-component regulatory system controls bacitracin resistance in Bacillus subtilis.

PubMed

Dintner, Sebastian; Heermann, Ralf; Fang, Chong; Jung, Kirsten; Gebhard, Susanne

2014-10-03

Resistance against antimicrobial peptides in many Firmicutes bacteria is mediated by detoxification systems that are composed of a two-component regulatory system (TCS) and an ATP-binding cassette (ABC) transporter. The histidine kinases of these systems depend entirely on the transporter for sensing of antimicrobial peptides, suggesting a novel mode of signal transduction where the transporter constitutes the actual sensor. The aim of this study was to investigate the molecular mechanisms of this unusual signaling pathway in more detail, using the bacitracin resistance system BceRS-BceAB of Bacillus subtilis as an example. To analyze the proposed communication between TCS and the ABC transporter, we characterized their interactions by bacterial two-hybrid analyses and could show that the permease BceB and the histidine kinase BceS interact directly. In vitro pulldown assays confirmed this interaction, which was found to be independent of bacitracin. Because it was unknown whether BceAB-type transporters could detect their substrate peptides directly or instead recognized the peptide-target complex in the cell envelope, we next analyzed substrate binding by the transport permease, BceB. Direct and specific binding of bacitracin by BceB was demonstrated by surface plasmon resonance spectroscopy. Finally, in vitro signal transduction assays indicated that complex formation with the transporter influenced the autophosphorylation activity of the histidine kinase. Taken together, our findings clearly show the existence of a sensory complex composed of TCS and ABC transporters and provide the first functional insights into the mechanisms of stimulus perception, signal transduction, and antimicrobial resistance employed by Bce-like detoxification systems. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

PEGylated Self-Assembled Nano-Bacitracin A: Probing the Antibacterial Mechanism and Real-Time Tracing of Target Delivery in Vivo.

PubMed

Hong, Wei; Zhao, Yining; Guo, Yuru; Huang, Chengcheng; Qiu, Peng; Zhu, Jia; Chu, Chun; Shi, Hong; Liu, Mingchun

2018-04-04

Although nano-self-assemblies of hydrophobic-modified bacitracin A with poly(d,l-lactic- co-glycolic acid) (PLGA) (nano-BA PLGA ) have demonstrated promising antibacterial activities, the application of nano-BA PLGA was severely compromised by low water solubility. In this study, a series of PEGylated PLGA copolymers were selected to conjugate with the N-terminus of bacitracin A to construct PEGylated self-assembled nano-BAs and to further develop nano-self-assemblies of bacitracin A with strong antibacterial potency and high solubility. Compared with nano-BA PLGA , all PEGylated nano-BAs, except nano-BA 5k , exhibited strong antibacterial efficiency against both Gram-positive and Gram-negative bacteria by inducing loss of cytoplasmic membrane potential, membrane permeabilization, and leakage of calcein from artificial cell membranes. Studies elucidating the underlying mechanism of PEGylated nano-BAs against Gram-negative bacteria indicated that the strong hydrophobic and van der Waals interactions between PLGA and lipopolysaccharide (LPS) could bind, neutralize, and disassociate LPS, facilitating cellular uptake of the nanoparticles, which could destabilize the membrane, resulting in cell death. Moreover, PEGylated nano-BAs (nano-BA 12k ) with a longer PLGA block were expected to occupy a higher local density of BA mass on the surface and result in stronger hydrophobic and van der Waals interactions with LPS, which were responsible for the enhanced antibacterial activity against Gram-positive and emerging antibacterial activity against Gram-negative bacteria, respectively. In vivo imaging verified that PEGylated nano-BAs exhibited higher inflammatory tissue distribution and longer circulation time than nano-BA PLGA . Therefore, although PEGylation did not affect antibacterial activity, it is necessary for target delivery and resistance to clearance of the observed PEGylated nano-BAs. In vivo, nano-BA 12k also showed the highest therapeutic index against infection

Synthesis, construction, and evaluation of self-assembled nano-bacitracin A as an efficient antibacterial agent in vitro and in vivo.

PubMed

Hong, Wei; Gao, Xiang; Qiu, Peng; Yang, Jie; Qiao, Mingxi; Shi, Hong; Zhang, Dexian; Tian, Chunlian; Niu, Shengli; Liu, Mingchun

2017-01-01

Bacitracin A (BA) is an excellent polypeptide antibiotic that is active against gram-positive bacteria without triggering multidrug resistance. However, BA is inactive against gram-negative bacteria because of its inability to cross the outer membrane of these cells, and it has strong nephrotoxicity, thus limiting its clinical applications. Nanoantibiotics can effectively localize antibiotics to the periplasmic space of bacteria while decreasing the adverse effects of antibiotics. In this study, biodegradable hydrophobic copolymers of poly (d,l-lactide-co-glycolide) (PLGA) were attached to the N-termini of BA to design a novel class of self-assembled nano-bacitracin A (nano-BAs), and their potential as antibacterial agents was evaluated in vitro and in vivo. Nano-BAs had a core-shell structure with a mean diameter <150 nm. Impressively, nano-BAs had strong antibacterial properties against both gram-positive and gram-negative bacteria, and the distribution of antibacterial activity as a function of PLGA block length was skewed toward longer PLGA chains. No cytotoxicity against HK-2 cells or human red blood cells (hRBCs) was observed in vitro, suggesting good biocompatibility. A high local density of BA mass on the surface promoted endocytotic cellular uptake, and hydrophobic interactions between the PLGA block and lipopolysaccharide (LPS) facilitated the uptake of nano-BAs, thereby leading to greater antibacterial activities. In addition, Nano-BA 5K was found to be effective in vivo, and it served as an anti-infective agent for wound healing. Collectively, this study provides a cost-effective means of developing self-assembling nano-polypeptide antibiotic candidates with a broader antibacterial spectrum and a lower toxicity than commercially available peptide antibiotics, owing to their modification with biodegradable copolymers.

Synthesis, construction, and evaluation of self-assembled nano-bacitracin A as an efficient antibacterial agent in vitro and in vivo

PubMed Central

Hong, Wei; Gao, Xiang; Qiu, Peng; Yang, Jie; Qiao, Mingxi; Shi, Hong; Zhang, Dexian; Tian, Chunlian; Niu, Shengli; Liu, Mingchun

2017-01-01

Bacitracin A (BA) is an excellent polypeptide antibiotic that is active against gram-positive bacteria without triggering multidrug resistance. However, BA is inactive against gram-negative bacteria because of its inability to cross the outer membrane of these cells, and it has strong nephrotoxicity, thus limiting its clinical applications. Nanoantibiotics can effectively localize antibiotics to the periplasmic space of bacteria while decreasing the adverse effects of antibiotics. In this study, biodegradable hydrophobic copolymers of poly (d,l-lactide-co-glycolide) (PLGA) were attached to the N-termini of BA to design a novel class of self-assembled nano-bacitracin A (nano-BAs), and their potential as antibacterial agents was evaluated in vitro and in vivo. Nano-BAs had a core-shell structure with a mean diameter <150 nm. Impressively, nano-BAs had strong antibacterial properties against both gram-positive and gram-negative bacteria, and the distribution of antibacterial activity as a function of PLGA block length was skewed toward longer PLGA chains. No cytotoxicity against HK-2 cells or human red blood cells (hRBCs) was observed in vitro, suggesting good biocompatibility. A high local density of BA mass on the surface promoted endocytotic cellular uptake, and hydrophobic interactions between the PLGA block and lipopolysaccharide (LPS) facilitated the uptake of nano-BAs, thereby leading to greater antibacterial activities. In addition, Nano-BA5K was found to be effective in vivo, and it served as an anti-infective agent for wound healing. Collectively, this study provides a cost-effective means of developing self-assembling nano-polypeptide antibiotic candidates with a broader antibacterial spectrum and a lower toxicity than commercially available peptide antibiotics, owing to their modification with biodegradable copolymers. PMID:28721045

Experimental stroke protection induced by 4-hydroxybenzyl alcohol is cancelled by bacitracin.

PubMed

Descamps, Elodie; Petrault-Laprais, Maud; Maurois, Pierre; Pages, Nicole; Bac, Pierre; Bordet, Régis; Vamecq, Joseph

2009-06-01

Induction of protein disulfide isomerase (PDI) is validated as a main mechanism by which 4-hydroxybenzyl alcohol (4-HBA), an active principle of Gastrodia elata Blume, reduces cerebral infarct volumes in a murine model of focal brain ischemia/reperfusion. In contrast to its position isomers, i.e. 3-hydroxybenzyl alcohol (3-HBA) and 2-hydroxybenzyl alcohol (2-HBA), and to aliphatic diols (1,4-butanediol and 1,5-pentanediol), 4-HBA administered intravenously at 25 mg/kg protected mice, significantly reducing total, cortical and sub-cortical infarct volumes by 42, 28 and 55%, respectively. All compounds, 4-HBA included, were devoid of antioedematous properties. Only the stroke protective 4-HBA, but neither 3-HBA nor 2-HBA, was capable of significantly inducing PDI in intact mouse brains. Stroke protection was fully prevented by bacitracin (500 mg/kg), a known inhibitor of PDI, which, without affecting basal brain PDI levels, altered the ability of 4-HBA to induce significantly PDI in intact brains. Taken as a whole, our data indicate that stroke protection induced by 4-HBA involves PDI as a key player, making this protein a valuable target to control brain injury disorders. The fact that 4-HBA, at doses up to 200mg/kg, was devoid of neurotoxicity in the rotarod test is also a decisive element to promote the neuroprotective use of this plant compound.

21 CFR 558.274 - Hygromycin B.

Code of Federal Regulations, 2011 CFR

2011-04-01

... methylene disalicylate or zinc bacitracin; withdraw 3 days before slaughter Bacitracin plus penicillin (100...% of penicillin plus not less than 50% of bacitracin; as procaine penicillin plus bacitracin methylene... penicillin; as procaine penicillin plus zinc bacitracin; withdraw 3 days before slaughter 3. Chickens...

21 CFR 558.274 - Hygromycin B.

Code of Federal Regulations, 2010 CFR

2010-04-01

... methylene disalicylate or zinc bacitracin; withdraw 3 days before slaughter Bacitracin plus penicillin (100...% of penicillin plus not less than 50% of bacitracin; as procaine penicillin plus bacitracin methylene... penicillin; as procaine penicillin plus zinc bacitracin; withdraw 3 days before slaughter 3. Chickens...

Postoperative infections in colonic surgery after enteral bacitracin-neomycin-clindamycin or parenteral mezlocillin-oxacillin prophylaxis.

PubMed

Schiessel, R; Huk, I; Starlinger, M; Wunderlich, M; Rotter, M; Wewalka, G; Schemper, M

1984-09-01

In a prospective randomized, blind trial, three groups of patients undergoing elective colonic surgery were compared for frequency of surgical wound infection, intra-operative wound contamination and other postoperative infections. All patients allotted to the three groups received whole gut irrigation (101 balanced salt solution) by gastric tube on the evening before surgery and were treated as follows. Group A: no antibiotics; Group B: neomycin (1 g/l) + bacitracin (50,000 IU/l) + clindamycin (900 mg/l), contained in the last 31 of irrigation fluid; Group C: mezlocillin (4 g) + oxacillin (2 g) intravenously (iv) at induction of anaesthesia, followed by two identical doses at 8 and 16 h. The rate of postoperative wound infection was highest in A (38 per cent) and much lower in B (3.3 per cent, P less than 0.002) and C (6.9 per cent, P less than 0.004). The difference between B and C was statistically not significant. In A a correlation was established between the degree of wound contamination and the occurrence of wound infection. Intra-operative wound contamination was lowest in B (30 per cent), equal in A (58.1 per cent) and B (55.2 per cent). Other infections were least frequent in group C (four of 29 patients), but were not significantly different to groups B (six of 30) and A (nine of 31). It is concluded that antibiotics together with an effective mechanical preparation considerably reduce the rate of wound infection in colonic surgery.

Effect of zinc bacitracin and phytase on growth performance, nutrient digestibility, carcass and meat traits of broilers.

PubMed

Attia, Y A; Bovera, F; Abd El-Hamid, A E; Tag El-Din, A E; Al-Harthi, M A; El-Shafy, A S

2016-06-01

A total of 336 one-day-old Hubbard broiler chickens were randomly distributed among 8 groups, each containing six replicates (7 chickens/replicate). From 1 to 40 days of age, the groups fed the same starter, grower and finisher diets. The control group was unsupplemented; zinc bacitracin (ZnB) group received the antibiotic at 0.5 g/kg; fungal phytase (FP) groups received 250, 500 and 1000 U/kg diet of Aspergillus niger phytase (FP_250, FP_500 and FP_1000 groups), respectively; bacterial phyatse (BP) groups received 250, 500 and 1000 U/kg diet of Escherichia coli phytase (BP_250EP, BP_500EP and BP_1000EP groups) respectively. Considering the whole experimental period, body weight gain was unaffected by ZnB and different concentrations of bacterial and fungal phytase; however, the feed conversion ratio of the group fed a diet supplemented with 500 U of BP was better (p < 0.01) than those fed with a diet supplemented with 500 U of FP. BP_250 group had a higher (p < 0.05) apparent digestibility of ether extract compared to FP_250 group. In conclusion, bacterial phytase at 500 U may enhance performance of broiler chickens fed during days 1-40 of age and yield similar growth performance and economic efficiency to those of eB-supplemented groups. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

21 CFR 333.120 - Permitted combinations of active ingredients.

Code of Federal Regulations, 2013 CFR

2013-04-01

... gram, 500 units of bacitracin and 3.5 milligrams of neomycin in a suitable ointment base. (2) Bacitracin-neomycin sulfate-polymyxin B sulfate ointment containing, in each gram, in a suitable ointment...) Bacitracin-polymyxin B sulfate topical aerosol containing, in each gram, 500 units of bacitracin and 5,000...

21 CFR 333.120 - Permitted combinations of active ingredients.

Code of Federal Regulations, 2011 CFR

2011-04-01

... gram, 500 units of bacitracin and 3.5 milligrams of neomycin in a suitable ointment base. (2) Bacitracin-neomycin sulfate-polymyxin B sulfate ointment containing, in each gram, in a suitable ointment...) Bacitracin-polymyxin B sulfate topical aerosol containing, in each gram, 500 units of bacitracin and 5,000...

21 CFR 333.120 - Permitted combinations of active ingredients.

Code of Federal Regulations, 2010 CFR

2010-04-01

... gram, 500 units of bacitracin and 3.5 milligrams of neomycin in a suitable ointment base. (2) Bacitracin-neomycin sulfate-polymyxin B sulfate ointment containing, in each gram, in a suitable ointment...) Bacitracin-polymyxin B sulfate topical aerosol containing, in each gram, 500 units of bacitracin and 5,000...

21 CFR 333.120 - Permitted combinations of active ingredients.

Code of Federal Regulations, 2012 CFR

2012-04-01

... gram, 500 units of bacitracin and 3.5 milligrams of neomycin in a suitable ointment base. (2) Bacitracin-neomycin sulfate-polymyxin B sulfate ointment containing, in each gram, in a suitable ointment...) Bacitracin-polymyxin B sulfate topical aerosol containing, in each gram, 500 units of bacitracin and 5,000...

21 CFR 333.120 - Permitted combinations of active ingredients.

Code of Federal Regulations, 2014 CFR

2014-04-01

... gram, 500 units of bacitracin and 3.5 milligrams of neomycin in a suitable ointment base. (2) Bacitracin-neomycin sulfate-polymyxin B sulfate ointment containing, in each gram, in a suitable ointment...) Bacitracin-polymyxin B sulfate topical aerosol containing, in each gram, 500 units of bacitracin and 5,000...

Protein disulfide isomerase regulates renal AT1 receptor function and blood pressure in rats.

PubMed

Wang, Xitao; Asghar, Mohammad

2017-08-01

The role and mechanism of renal protein disulfide isomerase (PDI) in blood pressure regulation has not been tested before. Here, we test this possibility in Sprague-Dawley rats. Rats were treated with PDI inhibitor bacitracin (100 mg·kg -1 ip·day -1 for 14 days), and then blood pressure and renal angiotensin II type 1 (AT 1 ) receptor function were determined in anesthetized rats. Renal AT 1 receptor function was determined as the ability of candesartan (an AT 1 receptor blocker) to increase diuresis and natriuresis. A second set of vehicle- and bacitracin-treated rats was used to determine biochemical parameters. Systolic blood pressure as well as diastolic blood pressure increased in bacitracin-treated compared with vehicle-treated rats. Compared with vehicle, bacitracin-treated rats showed increased diuresis and natriuresis in response to candesartan (10-µg iv bolus dose) suggesting higher AT 1 receptor function in these rats. These were associated with higher renin activities in the plasma and renal tissues. Furthermore, urinary 8-isoprostane and kidney injury molecule-1 levels were higher and urinary antioxidant capacity was lower in bacitracin-treated rats. Renal protein carbonyl and nitrotyrosine levels also were higher in bacitracin- compared with vehicle-treated rats, suggesting oxidative stress burden in bacitracin-treated rats. Moreover, PDI activity decreased and its protein levels increased in renal tissues of bacitracin-treated rats. Also, nuclear levels of Nrf2 transcription factor, which regulates redox homeostasis, were decreased in bacitracin-treated rats. Furthermore, tissue levels of Keap1, an Nrf2 inhibitory molecule, and tyrosine 216-phosphorylated GSK3β protein, an Nrf2 nuclear export protein, were increased in bacitracin-treated rats. These results suggest that renal PDI by regulating Keap1-Nrf2 pathway acts as an antioxidant, maintaining redox balance, renal AT 1 receptor function, and blood pressure in rats. Copyright © 2017 the

21 CFR 333.110 - First aid antibiotic active ingredients.

Code of Federal Regulations, 2013 CFR

2013-04-01

... and in the specified dosage form: (a) Bacitracin ointment containing, in each gram, 500 units of bacitracin in a suitable ointment base. (b) Bacitracin zinc ointment containing, in each gram, 500 units of... gram, 30 milligrams of chlortetracycline hydrochloride in a suitable ointment base. (d) Neomycin...

21 CFR 333.110 - First aid antibiotic active ingredients.

Code of Federal Regulations, 2012 CFR

2012-04-01

... and in the specified dosage form: (a) Bacitracin ointment containing, in each gram, 500 units of bacitracin in a suitable ointment base. (b) Bacitracin zinc ointment containing, in each gram, 500 units of... gram, 30 milligrams of chlortetracycline hydrochloride in a suitable ointment base. (d) Neomycin...

21 CFR 333.110 - First aid antibiotic active ingredients.

Code of Federal Regulations, 2010 CFR

2010-04-01

... and in the specified dosage form: (a) Bacitracin ointment containing, in each gram, 500 units of bacitracin in a suitable ointment base. (b) Bacitracin zinc ointment containing, in each gram, 500 units of... gram, 30 milligrams of chlortetracycline hydrochloride in a suitable ointment base. (d) Neomycin...

21 CFR 333.110 - First aid antibiotic active ingredients.

Code of Federal Regulations, 2011 CFR

2011-04-01

... and in the specified dosage form: (a) Bacitracin ointment containing, in each gram, 500 units of bacitracin in a suitable ointment base. (b) Bacitracin zinc ointment containing, in each gram, 500 units of... gram, 30 milligrams of chlortetracycline hydrochloride in a suitable ointment base. (d) Neomycin...

21 CFR 333.110 - First aid antibiotic active ingredients.

Code of Federal Regulations, 2014 CFR

2014-04-01

... and in the specified dosage form: (a) Bacitracin ointment containing, in each gram, 500 units of bacitracin in a suitable ointment base. (b) Bacitracin zinc ointment containing, in each gram, 500 units of... gram, 30 milligrams of chlortetracycline hydrochloride in a suitable ointment base. (d) Neomycin...

21 CFR 558.274 - Hygromycin B.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Bacitracin plus penicillin (100 to 200 of combination) 1. Chickens; control of infestation of large...) Feed containing not less than 25% of penicillin plus not less than 50% of bacitracin; as procaine penicillin plus bacitracin methylene disalicylate; withdraw 3 days before slaughter 2. Chickens; control of...

21 CFR 558.274 - Hygromycin B.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Bacitracin plus penicillin (100 to 200 of combination) 1. Chickens; control of infestation of large...) Feed containing not less than 25% of penicillin plus not less than 50% of bacitracin; as procaine penicillin plus bacitracin methylene disalicylate; withdraw 3 days before slaughter 2. Chickens; control of...

Alteration of digestive tract microbiome in neonatal Holstein bull calves by bacitracin methylene disalicylate treatment and scours.

PubMed

Xie, G; Duff, G C; Hall, L W; Allen, J D; Burrows, C D; Bernal-Rigoli, J C; Dowd, S E; Guerriero, V; Yeoman, C J

2013-10-01

The effects of bacitracin methylene disalicylate (BMD) and scours on the fecal microbiome, animal performance, and health were studied in Holstein bull calves. Holstein bull calves (n = 150) were obtained from a single source at 12 to 24 h of age. Bull calves were randomly assigned to 1 of 2 treatments including CON (no BMD; n = 75 calves) and BMD (n = 75 calves). Starting 3 d after arrival, BMD was added into milk replacer (0.5 g/feeding; twice daily) and fed to the calves for 10 consecutive d. No differences (P > 0.10) were observed in ADG for d 0 to 28 and d 0 to 56, DMI for d 0 to 28, d 29 to 56, and d 0 to 56, or G:F for d 0 to 28, d 29 to 56, and d 0 to 56; ADG for d 29 to 56 tended to increase (P < 0.10) for BMD-treated calves compared with controls. Fecal samples were collected from 15 scouring calves and 10 cohorts (nonscouring calves received on the same day and administered the same treatment as the scouring calves). Animal morbidity and fecal score did not vary between the 2 treatments. Mortality was not influenced by the treatments in the BMD administration period or throughout the experiment. Fecal samples were subjected to pyrotagged 454 FLX pyrosequencing of 16S rRNA gene amplicon to examine compositional dynamics of fecal microbes. Escherichia, Enterococcus, and Shigella had greater (P < 0.05) populations in the BMD group whereas Dorea, Roseburia, Fecalibacterium, Papillibacter, Collinsella, Eubacterium, Peptostreptococcus, and Prevotella were decreased (P < 0.05) by BMD treatment. Genus populations were also compared between scouring and nonscouring calves. Streptococcus was the only genus that had notable increase (P < 0.05) in fecal samples from scouring calves whereas populations of Bacteroides, Roseburia, and Eubacterium were markedly (P < 0.05) greater in nonscouring calves. These results show that BMD has the ability to alter the composition of the fecal microbiome but failed to improve performance in Holstein bull calves. Discrepancy of

Bacitracin Ophthalmic

MedlinePlus

... of medications called antibiotics. It works by killing bacteria that cause infections. ... infection may not be completely cured and the bacteria may become resistant to antibiotics.To use the ...

Bacitracin Topical

MedlinePlus

... area, do not use tightly fitting diapers or plastic pants.To use the ointment, follow these steps: ... to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in ...

Bacitracin overdose

MedlinePlus

... amount of the product. This can be by accident or on purpose. This article is for information ... water for at least 15 minutes. If the chemical was swallowed, give the person water or milk right ... A.D.A.M.'s editorial policy , editorial process and privacy policy . A.D.A.M. is ...

Effects of replacing a dietary antibacterial agent (zinc bacitracin) with copper salts in Cherry Valley Pekin meat ducks.

PubMed

Wu, D W; Wang, L C; Wen, C; Hooge, D M; Liang, C; Zhou, Y M

2013-01-01

1. A study was conducted to investigate the effectiveness of high dietary copper concentrations obtained from tribasic copper chloride (TBCC, 58% copper) and copper sulphate pentahydrate (CuSO4, 25% copper) in replacing antibiotic growth promoters (AGP) in duck diets. 2. A total of 960 one-day-old Cherry Valley meat-strain ducks were divided into 3 treatment groups, with 8 replicates per treatment, in a 6-week feeding trial. The ducks were fed a basal diet supplemented with AGP (40 mg zinc bacitracin/kg and 40 mg garlicin/kg of diet) or 150 mg of Cu/kg of diet, given as either CuSO4 or TBCC. 3. The body weight, average daily gain, average daily feed intake and mortality of ducks were not affected by the dietary treatments. However, the feed/gain ratio of ducks that were fed TBCC diets was significantly lower than those of ducks that were fed CuSO4 diets and were similar to those in the AGP group. 4. TBCC increased the Cu content in the liver tissue of ducks compared with the content in those that were fed the diet supplemented with AGP. TBCC also increased the Fe and Zn content in breast muscles compared with that in ducks that were fed the diet supplemented with CuSO4. 5. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were significantly higher in the serum of ducks that received the diet supplemented with TBCC than AGP or CuSO4. TBCC treatment decreased the malondialdehyde (MDA) content in serum of ducks compared with groups supplemented with CuSO4. 6. No significant difference was observed in liver or muscle fat content among the different dietary treatment groups. The serum low-density lipoprotein cholesterol concentration was lower in ducks fed AGP diets than those fed CuSO4 diets. 7. It was concluded that the replacement of AGP with 150 mg of Cu/kg of feed from TBCC improved the feed efficiency, trace mineral deposition and antioxidant status more than when the source of copper was CuSO4.

Bacitracin zinc overdose

MedlinePlus

... amount of the product. This can be by accident or on purpose. This article is for information ... water for at least 15 minutes. If the chemical was swallowed, immediately give the person water or ... A.D.A.M.'s editorial policy , editorial process and privacy policy . A.D.A.M. is ...

Is substance P released from slices of the rat spinal cord inactivated by peptidase(s) distinct from both 'enkephalinase' and 'angiotensin-converting enzyme'?

PubMed

Mauborgne, A; Bourgoin, S; Benoliel, J J; Hamon, M; Cesselin, F

1991-02-25

Studies on the effects of peptidase inhibitors on substance P-like immunoreactive material (SPLI) released by K(+)-induced depolarization from slices of the rat spinal cord showed that bacitracin was the most potent agent to protect SPLI from degradation. Captopril and thiorphan which inhibit, respectively, angiotensin I converting enzyme and endopeptidase-24.11 also protected SPLI from degradation. However other inhibitors of these two enzymes, kelatorphan for endopeptidase-24.11 and enalaprilat for angiotensin I converting enzyme were essentially inactive, indicating that both enzymes are probably not involved in the degradation of endogenous substance P. Instead, the non-additive protecting effect of bacitracin, captopril and thiorphan might be due to the blockade of some 'bacitracin-sensitive enzyme' playing a key role in the catabolism of SP within the rat spinal cord.

Identification of Streptococcus pyogenes - Phenotypic Tests vs Molecular Assay (spy1258PCR): A Comparative Study.

PubMed

Abraham, Tintu; Sistla, Sujatha

2016-07-01

Traditionally Group A Streptococcus pyogenes (GAS) is differentiated from other beta haemolytic streptococci (BHS) by certain presumptive tests such as bacitracin sensitivity and production of Pyrollidonyl Aryl Sulfatase (PYR). The phenotypic and genotypic confirmatory tests are Lancefield grouping for cell wall carbohydrate antigen and PCR for spy1258 gene respectively. Reliance on presumptive tests alone may lead to misidentification of isolates. To compare the predictive values of routine phenotypic tests with spy1258 PCR for the identification of Streptococcus pyogenes. This comparative analytical study was carried out in the Department of Microbiology, JIPMER, Puducherry, over a period of 18 months (1(st) November 2013 to 30(th) April 2015). Two hundred and six consecutive BHS isolates from various clinical samples were subjected to phenotypic tests such as bacitracin sensitivity, PYR test and Lancefield grouping. The results were compared with spy1258 PCR which was considered 95 the confirmatory test for identification. The sensitivity and specificity of phenotypic tests were as follows; Susceptibility to bacitracin - 95.42%, 70.96%, PYR test - 95.42%, 77.41%, Lancefield grouping- 97.71%, 80.64%. Clinical laboratories should not depend on bacitracin sensitivity as a single presumptive test for the routine identification of GAS but should use supplemental tests such as PYR test or latex agglutination test and for best results use spy1258 PCR.

Early prepubertal ontogeny of pulsatile gonadotropin-releasing hormone (GnRH) secretion: I. Inhibitory autofeedback control through prolyl endopeptidase degradation of GnRH.

PubMed

Yamanaka, C; Lebrethon, M C; Vandersmissen, E; Gerard, A; Purnelle, G; Lemaitre, M; Wilk, S; Bourguignon, J P

1999-10-01

GnRH[1-5], a subproduct resulting from degradation of GnRH by prolyl endopeptidase (PEP) and endopeptidase 24.15 (EP24.15) was known to account for an inhibitory autofeedback of GnRH secretion through an effect at the N-methyl-D-aspartate (NMDA) receptors. This study aimed at determining the possible role of such a mechanism in the early developmental changes in frequency of pulsatile GnRH secretion. Using retrochiasmatic explants from fetal male rats (day 20-21 of gestation), no GnRH pulses could be observed in vitro, whereas pulses occurred at a mean interval of 86 min from the day of birth onwards. This interval decreased steadily until day 25 (39 min), during the period preceding the onset of puberty. Based on GnRH[1-10] or GnRH[1-9] degradation and GnRH[1-5] generation after incubation with hypothalamic extracts, EP24.15 activity did not change with age, whereas PEP activity was maximal at days 5-10 and decreased subsequently until day 50. These changes were consistent with the ontogenetic variations in PEP messenger RNAs (mRNAs) quantitated using RT-PCR. Using fetal explants, the NMDA-evoked release of GnRH was potentiated in a dose-dependent manner by bacitracin, a competitive PEP inhibitor and the desensitization to the NMDA effect was prevented using 2 mM of bacitracin. At day 5, a higher bacitracin concentration of 20 mM was required for a similar effect. Pulsatile GnRH secretion from fetal explants was not caused to occur using bacitracin or Fmoc-Prolyl-Pyrrolidine-2-nitrile (Fmoc-Pro-PyrrCN), a noncompetitive PEP inhibitor. At postnatal days 5 and 15, a significant acceleration of pulsatility was obtained using 1 microM of Fmoc-Pro-PyrrCN or 2 mM of bacitracin. At 25 and 50 days, a lower bacitracin concentration of 20 microM was effective as well in increasing the frequency of GnRH pulsatility. We conclude that the GnRH inhibitory autofeedback resulting from degradation of the peptide is operational in the fetal hypothalamus but does not explain the

Neomycin, Polymyxin, and Bacitracin Topical

MedlinePlus

... area, do not use tightly fitting diapers or plastic pants.To use the ointment, follow these steps: ... to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in ...

21 CFR 524.154 - Bacitracin or bacitracin zinc-neomycin sulfate-polymyxin B sulfate ophthalmic ointment.

Code of Federal Regulations, 2011 CFR

2011-04-01

... organisms. (3) Limitations. Laboratory tests should be conducted including in vitro culturing and... sulfate ophthalmic ointment. (a) Sponsor. To firms identified in § 510.600(c) of this chapter as follows...

21 CFR 524.154 - Bacitracin or bacitracin zinc-neomycin sulfate-polymyxin B sulfate ophthalmic ointment.

Code of Federal Regulations, 2010 CFR

2010-04-01

... organisms. (3) Limitations. Laboratory tests should be conducted including in vitro culturing and... sulfate ophthalmic ointment. (a) Sponsor. To firms identified in § 510.600(c) of this chapter as follows...

The Two-Component System ChtRS Contributes to Chlorhexidine Tolerance in Enterococcus faecium.

PubMed

Guzmán Prieto, Ana M; Wijngaarden, Jessica; Braat, Johanna C; Rogers, Malbert R C; Majoor, Eline; Brouwer, Ellen C; Zhang, Xinglin; Bayjanov, Jumamurat R; Bonten, Marc J M; Willems, Rob J L; van Schaik, Willem

2017-05-01

Enterococcus faecium is one of the primary causes of nosocomial infections. Disinfectants are commonly used to prevent infections with multidrug-resistant E. faecium in hospitals. Worryingly, E. faecium strains that exhibit tolerance to disinfectants have already been described. We aimed to identify and characterize E. faecium genes that contribute to tolerance to the disinfectant chlorhexidine (CHX). We used a transposon mutant library, constructed in a multidrug-resistant E. faecium bloodstream isolate, to perform a genome-wide screen to identify genetic determinants involved in tolerance to CHX. We identified a putative two-component system (2CS), composed of a putative sensor histidine kinase (ChtS) and a cognate DNA-binding response regulator (ChtR), which contributed to CHX tolerance in E. faecium Targeted chtR and chtS deletion mutants exhibited compromised growth in the presence of CHX. Growth of the chtR and chtS mutants was also affected in the presence of the antibiotic bacitracin. The CHX- and bacitracin-tolerant phenotype of E. faecium E1162 was linked to a unique, nonsynonymous single nucleotide polymorphism in chtR Transmission electron microscopy showed that upon challenge with CHX, the Δ chtR and Δ chtS mutants failed to divide properly and formed long chains. Normal growth and cell morphology were restored when the mutations were complemented in trans Morphological abnormalities were also observed upon exposure of the Δ chtR and Δ chtS mutants to bacitracin. The tolerance to both chlorhexidine and bacitracin provided by ChtRS in E. faecium highlights the overlap between responses to disinfectants and antibiotics and the potential for the development of cross-tolerance for these classes of antimicrobials. Copyright © 2017 American Society for Microbiology.

Degradation of insulin by human fibroblasts: effects of inhibitors of pinocytosis and lysosomal activity.

PubMed

Kooistra, T; Lloyd, J B

1985-01-01

The role of the pinosome-lysosome pathway in the degradation of 125I-labelled bovine insulin by cultured human fibroblasts was examined by comparing the effects of various known inhibitors of pinocytosis and lysosomal degradation on the uptake and degradation of 125I-labelled polyvinylpyrrolidone, formaldehyde-denatured bovine serum albumin and bovine insulin by these cells. Fibroblasts incubated with polyvinylpyrrolidone steadily accumulate this substrate, whereas incubations with insulin or denatured albumin led to the progressive appearance in the culture medium of [125I]iodotyrosine. Inhibitors of pinocytosis (bacitracin, colchicine and monensin), metabolic inhibitors (2,4-dinitrophenol and NaF), lysosomotropic agents (chloroquine and NH4Cl) and an inhibitor of cysteine-proteinases (leupeptin) decreased the rate of uptake of polyvinylpyrrolidone and denatured albumin very similarly, but only bacitracin had an effect on the processing of insulin. Chloroquine, NH4Cl and leupeptin strongly inhibited the digestion of denatured albumin, but not of insulin. The different responses to the modifiers, with polyvinylpyrrolidone and denatured albumin on the one hand and insulin on the other, suggest that insulin degradation can occur by a non-lysosomal pathway. The very strong inhibitory effect of bacitracin on insulin processing by fibroblasts may point to an important role of plasma membrane proteinases in insulin degradation.

Nisin, alone and combined with peptidoglycan-modulating antibiotics: activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci.

PubMed

Brumfitt, W; Salton, M R J; Hamilton-Miller, J M T

2002-11-01

We have sought ways to circumvent resistance, by combining nisin with other antibiotics known to target bacterial cell wall biosynthesis. Twenty strains each of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) were tested in vitro by standardized methods against nisin alone and combined with bacitracin, ramoplanin and chloramphenicol. Ramoplanin was the most potent compound, and bacitracin had the least activity. Two-way synergy was observed with nisin and ramoplanin. However, chloramphenicol was clearly antagonistic to the activity of nisin. Observations of synergy between nisin and ramoplanin against MRSA and VRE offer a promising approach to the concept of combining nisin with inhibitors of cell wall peptidoglycan. Further investigations are needed in order to develop this approach as a clinical possibility.

21 CFR 558.78 - Bacitracin zinc.

Code of Federal Regulations, 2014 CFR

2014-04-01

... feed efficiency Growing chickens 054771 (ii) 4 to 50 Turkeys and pheasants: for increased rate of weight gain and improved feed efficiency Growing turkeys and pheasants 054771 (iii) 5 to 20 Quail; for...

Hamstring graft bacterial contamination during anterior cruciate ligament reconstruction: clinical and microbiological study.

PubMed

Badran, Mohamad Aboelnour; Moemen, Dalia Mohamed

2016-09-01

Autograft preparation for anterior cruciate ligament (ACL) reconstruction has a potential for graft contamination. The purpose of this study was to evaluate the possibility of bacterial contamination of hamstring autograft during preparation and when dropped onto the operating room floor and methods of graft decontamination. Sixty hamstring tendon autograft specimens were used as the test group. Excess tendon not used in the ACL procedure was divided into five segments. One segment, at the completion of preparation, was sent for culture as a control; the remaining four segments were dropped onto the floor adjacent to the surgical field for 15 seconds. One segment was cultured without undergoing any further treatment. Cultures were taken from each segment after immersion in 10 % povidone-iodine solution, 4 % chlorhexidine and bacitracin, respectively, for three minutes. Cultures of a skin swab and floor swab were taken at the same time and place that the ACL was dropped. Cultures of control graft tissue from ten patients (16.7 %) were positive for bacteria. No patient developed post-operative infection. Ninety organisms were identified, with Staphylococcus epidermidis being the most common isolate. Grafts rinsed in either bacitracin or 4 % chlorhexidine solutions were less likely to be culture positive. A high rate of contamination can be expected during autograft preparation for ACL reconstruction. Soaking the hamstring autograft in either bacitracin or 4 % chlorhexidine solution is effective for decontamination, particulary if graft is dropped on the floor.

A Transposon Screen Identifies Genetic Determinants of Vibrio cholerae Resistance to High-Molecular-Weight Antibiotics

PubMed Central

Delgado, Fernanda; Umans, Benjamin D.; Gerding, Matthew A.; Davis, Brigid M.

2016-01-01

Gram-negative bacteria are notoriously resistant to a variety of high-molecular-weight antibiotics due to the limited permeability of their outer membrane (OM). The basis of OM barrier function and the genetic factors required for its maintenance remain incompletely understood. Here, we employed transposon insertion sequencing to identify genes required for Vibrio cholerae resistance to vancomycin and bacitracin, antibiotics that are thought to be too large to efficiently penetrate the OM. The screen yielded several genes whose protein products are predicted to participate in processes important for OM barrier functions and for biofilm formation. In addition, we identified a novel factor, designated vigA (for vancomycin inhibits growth), that has not previously been characterized or linked to outer membrane function. The vigA open reading frame (ORF) codes for an inner membrane protein, and in its absence, cells became highly sensitive to glycopeptide antibiotics (vancomycin and ramoplanin) and bacitracin but not to other large antibiotics or detergents. In contrast to wild-type (WT) cells, the vigA mutant was stained with fluorescent vancomycin. These observations suggest that VigA specifically prevents the periplasmic accumulation of certain large antibiotics without exerting a general role in the maintenance of OM integrity. We also observed marked interspecies variability in the susceptibilities of Gram-negative pathogens to glycopeptides and bacitracin. Collectively, our findings suggest that the OM barrier is not absolute but rather depends on specific OM-antibiotic interactions. PMID:27216069

SXT and Taxo A Disks for Presumptive Identification of Group A and B Streptococci in Throat Cultures

PubMed Central

Gunn, Bruce A.

1976-01-01

A bacitracin (0.04 units, BBL)-SXT (trimethoprim, 1.25 mg, plus sulfamethoxazole, 23.75 mg, BBL) susceptibility test was 94% accurate in presumptively identifying streptococci as either group A, B or not group A and B. PMID:965480

21 CFR 558.76 - Bacitracin methylene disalicylate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... gramsper ton Indications for use Limitations Sponsor (i) 4 to 50 Chickens, turkeys, and pheasants... age; increased rate of weight gain and improved feed efficiency 1 046573 (iii) 10 to 25 Chickens; for... Salmonella choleraesuis and bacterial pneumonia caused by Pasteurella multocida susceptible to...

21 CFR 558.76 - Bacitracin methylene disalicylate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... gramsper ton Indications for use Limitations Sponsor (i) 4 to 50 Chickens, turkeys, and pheasants... age; increased rate of weight gain and improved feed efficiency 1 046573 (iii) 10 to 25 Chickens; for... Salmonella choleraesuis and bacterial pneumonia caused by Pasteurella multocida susceptible to...

21 CFR 558.76 - Bacitracin methylene disalicylate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... gramsper ton Indications for use Limitations Sponsor (i) 4 to 50 Chickens, turkeys, and pheasants... age; increased rate of weight gain and improved feed efficiency 1 046573 (iii) 10 to 25 Chickens; for... Salmonella choleraesuis and bacterial pneumonia caused by Pasteurella multocida susceptible to...

21 CFR 558.76 - Bacitracin methylene disalicylate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... gramsper ton Indications for use Limitations Sponsor (i) 4 to 50 Chickens, turkeys, and pheasants... age; increased rate of weight gain and improved feed efficiency 1 046573 (iii) 10 to 25 Chickens; for... Salmonella choleraesuis and bacterial pneumonia caused by Pasteurella multocida susceptible to...

21 CFR 558.76 - Bacitracin methylene disalicylate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... gramsper ton Indications for use Limitations Sponsor (i) 4 to 50 Chickens, turkeys, and pheasants... age; increased rate of weight gain and improved feed efficiency 1 054771 (iii) 10 to 25 Chickens; for... Salmonella choleraesuis and bacterial pneumonia caused by Pasteurella multocida susceptible to...

Streptococcus pyogenes as the cause of vulvovaginitis and balanitis in children.

PubMed

Randjelovic, Gordana; Otasevic, Suzana; Mladenovic-Antic, Snezana; Mladenovic, Vesna; Radovanovic-Velickovic, Radmila; Randjelovic, Marina; Bogdanovic, Dragan

2017-04-01

Streptococcus pyogenes (group A Streptococcus) is the etiological agent of perineal infection in children, consisting of perianal infection, vulvovaginitis and balanitis. If it is not properly diagnosed and treated, it can persist for many months and can cause severe complications. Furthermore, treatment with penicillin can be followed by failures and recurrences. We report here the prevalence of S. pyogenes isolates in genital tract specimens from girls (n = 1692) with symptoms of vulvovaginitis and from boys (n = 52) with balanitis in the municipality of Nis, Southeast-Serbia (the Western Balkans) in a 10 year period, and the seasonal distribution, patient age and sensitivity to bacitracin and antimicrobial drugs used in the treatment of streptococcal infection. Streptococcal vulvovaginitis was diagnosed in 2.30% of examinees. Of those cases, 64.10% were detected from April to September, and it was most common (71.79%) in girls aged 3-7 years. Streptococcal balanitis was diagnosed in two instances: in a 4-year-old boy and in a 7-year-old boy. S. pyogenes strains resistant to bacitracin were identified in five girls. Two isolates with M phenotype and five isolates with cMLS B phenotype were identified. Streptococcal vulvovaginitis was diagnosed less often in the present study, but it was still far more common than streptococcal balanitis in childhood. Bacitracin resistance of S. pyogenes strains should be taken into account in routine microbiological identification, and the detection of S. pyogenes isolates resistant to erythromycin requires surveillance in the present geographical territory. © 2016 Japan Pediatric Society.

Effect of citral and carvacrol on the susceptibility of Listeria monocytogenes and Listeria innocua to antibiotics.

PubMed

Zanini, S F; Silva-Angulo, A B; Rosenthal, A; Rodrigo, D; Martínez, A

2014-05-01

The aim of this study was to evaluate the antibiotic susceptibility of Listeria innocua (L. innocua) and Listeria monocytogenes (L. monocytogenes) cells in the presence of citral and carvacrol at sublethal concentrations in an agar medium. The presence of terpenes in the L. monocytogenes and L. innocua culture medium provided a reduction in the minimal inhibitory concentration (MIC) of all the antibiotics tested. These effects were dependent on the concentration of terpenes present in the culture medium. The combination of citral and carvacrol potentiated antibiotic activity by reducing the MIC values of bacitracin and colistin from 32.0 and 128.0 μg ml⁻¹ to 1.0 and 2.0 μg ml⁻¹, respectively. Thus, both Listeria species became more susceptible to these drugs. In this way, the colistin and bacitracin resistance of L. monocytogenes and L. innocua was reversed in the presence of terpenes. Results obtained in this study show that the phytochemicals citral and carvacrol potentiate antibiotic activity, reducing the MIC values of cultured L. monocytogenes and L. innocua. Phytochemicals citral and carvacrol potentiate antibiotic activity of erythromycin, bacitracin and colistin by reducing the MIC values of cultured Listeria monocytogenes and Listeria innocua. This effect in reducing the MIC values of the antibiotics tested in both micro-organisms was increased when natural antimicrobials were combined. This finding indicated that the combination among terpenes and antibiotic may contribute in reducing the required dosage of antibiotics due to the possible effect of terpenes on permeation barrier of the micro-organism cell membrane. © 2014 The Society for Applied Microbiology.

An alternative to antibiotic-based drugs in feed for enhancing performance of broilers grown on Eimeria spp.-infected litter.

PubMed

Stanley, V G; Gray, C; Daley, M; Krueger, W F; Sefton, A E

2004-01-01

Three trials were conducted to evaluate the effects of lasalocid, an anticoccidial feed additive (90.7 kg/ton); bacitracin, a growth-promoter (50 g/ton); and yeast culture residue (YCR) (1 kg/ton) on the performance of broiler chicks reared to 42 d of age on recycled litter. Recycled litter consisted of pine wood shavings containing droppings from chicks infected with 3 select strains of coccidia (Eimeria tenella, Eimeria maxima, and Eimeria acervulina). Response variables (BW, intestinal tract and litter coliform counts, cecal and liver relative weights, and litter moisture content) were recorded biweekly. Mean BW of chicks fed the diet supplemented with YCR was higher than that of the controls (P < 0.05) and comparable to that of the lasalocid-treated birds in all 3 trials. Mean BW of chicks in all treatment groups decreased uniformly as the litter aged and moisture content increased. The mean intestinal coliform population from YCR-treated chicks was lower (P < 0.05) than those of the control and lasalocid populations. The coliform count was consistently lower than that in chicks on a bacitracin-supplemented diet. Coliform counts from the control and lasalocid-treated birds did not differ. The litter coliform counts increased with increased use of the litter. Cecal and liver relative weights calculated from the chicks in trial 3 showed that only the liver was significantly affected by treatments. YCR appeared to be a viable alternative to bacitracin and lasalocid medication in enhancing growth of broiler chicks reared on recycled litter.

Bacillus subtilis as a Platform for Molecular Characterisation of Regulatory Mechanisms of Enterococcus faecalis Resistance against Cell Wall Antibiotics

PubMed Central

Fang, Chong; Stiegeler, Emanuel; Cook, Gregory M.; Mascher, Thorsten; Gebhard, Susanne

2014-01-01

To combat antibiotic resistance of Enterococcus faecalis, a better understanding of the molecular mechanisms, particularly of antibiotic detection, signal transduction and gene regulation is needed. Because molecular studies in this bacterium can be challenging, we aimed at exploiting the genetically highly tractable Gram-positive model organism Bacillus subtilis as a heterologous host. Two fundamentally different regulators of E. faecalis resistance against cell wall antibiotics, the bacitracin sensor BcrR and the vancomycin-sensing two-component system VanSB-VanRB, were produced in B. subtilis and their functions were monitored using target promoters fused to reporter genes (lacZ and luxABCDE). The bacitracin resistance system BcrR-BcrAB of E. faecalis was fully functional in B. subtilis, both regarding regulation of bcrAB expression and resistance mediated by the transporter BcrAB. Removal of intrinsic bacitracin resistance of B. subtilis increased the sensitivity of the system. The lacZ and luxABCDE reporters were found to both offer sensitive detection of promoter induction on solid media, which is useful for screening of large mutant libraries. The VanSB-VanRB system displayed a gradual dose-response behaviour to vancomycin, but only when produced at low levels in the cell. Taken together, our data show that B. subtilis is a well-suited host for the molecular characterization of regulatory systems controlling resistance against cell wall active compounds in E. faecalis. Importantly, B. subtilis facilitates the careful adjustment of expression levels and genetic background required for full functionality of the introduced regulators. PMID:24676422

Bacillus subtilis as a platform for molecular characterisation of regulatory mechanisms of Enterococcus faecalis resistance against cell wall antibiotics.

PubMed

Fang, Chong; Stiegeler, Emanuel; Cook, Gregory M; Mascher, Thorsten; Gebhard, Susanne

2014-01-01

To combat antibiotic resistance of Enterococcus faecalis, a better understanding of the molecular mechanisms, particularly of antibiotic detection, signal transduction and gene regulation is needed. Because molecular studies in this bacterium can be challenging, we aimed at exploiting the genetically highly tractable Gram-positive model organism Bacillus subtilis as a heterologous host. Two fundamentally different regulators of E. faecalis resistance against cell wall antibiotics, the bacitracin sensor BcrR and the vancomycin-sensing two-component system VanSB-VanRB, were produced in B. subtilis and their functions were monitored using target promoters fused to reporter genes (lacZ and luxABCDE). The bacitracin resistance system BcrR-BcrAB of E. faecalis was fully functional in B. subtilis, both regarding regulation of bcrAB expression and resistance mediated by the transporter BcrAB. Removal of intrinsic bacitracin resistance of B. subtilis increased the sensitivity of the system. The lacZ and luxABCDE reporters were found to both offer sensitive detection of promoter induction on solid media, which is useful for screening of large mutant libraries. The VanSB-VanRB system displayed a gradual dose-response behaviour to vancomycin, but only when produced at low levels in the cell. Taken together, our data show that B. subtilis is a well-suited host for the molecular characterization of regulatory systems controlling resistance against cell wall active compounds in E. faecalis. Importantly, B. subtilis facilitates the careful adjustment of expression levels and genetic background required for full functionality of the introduced regulators.

21 CFR 558.366 - Nicarbazin.

Code of Federal Regulations, 2010 CFR

2010-04-01

... allow rabbits, hamsters, guinea pigs, horses, or ruminants access to feeds containing lincomycin... laying hens in production. Nicarbazin as provided by No. 066104; bacitracin methylene disalicylate and... consumption to allow for elimination of the drug from edible tissue. Do not feed to laying hens in production...

FDA-approved drugs that protect mammalian neurons from glucose toxicity slow aging dependent on cbp and protect against proteotoxicity.

PubMed

Lublin, Alex; Isoda, Fumiko; Patel, Harshil; Yen, Kelvin; Nguyen, Linda; Hajje, Daher; Schwartz, Marc; Mobbs, Charles

2011-01-01

Screening a library of drugs with known safety profiles in humans yielded 30 drugs that reliably protected mammalian neurons against glucose toxicity. Subsequent screening demonstrated that 6 of these 30 drugs increase lifespan in C. elegans: caffeine, ciclopirox olamine, tannic acid, acetaminophen, bacitracin, and baicalein. Every drug significantly reduced the age-dependent acceleration of mortality rate. These protective effects were blocked by RNAi inhibition of cbp-1 in adults only, which also blocks protective effects of dietary restriction. Only 2 drugs, caffeine and tannic acid, exhibited a similar dependency on DAF-16. Caffeine, tannic acid, and bacitracin also reduced pathology in a transgenic model of proteotoxicity associated with Alzheimer's disease. These results further support a key role for glucose toxicity in driving age-related pathologies and for CBP-1 in protection against age-related pathologies. These results also provide novel lead compounds with known safety profiles in human for treatment of age-related diseases, including Alzheimer's disease and diabetic complications.

Real-Time Quantitative PCR Measurement of Ileal Lactobacillus salivarius Populations from Broiler Chickens To Determine the Influence of Farming Practices▿ †

PubMed Central

Harrow, Sally A.; Ravindran, Velmurugu; Butler, Ruth C.; Marshall, John W.; Tannock, Gerald W.

2007-01-01

A real-time quantitative PCR assay targeting a 16S-23S intergenic spacer region sequence was devised to measure the sizes of populations of Lactobacillus salivarius present in ileal digesta collected from broiler chickens. This species has been associated with deconjugation of bile salts in the small bowel and reduced broiler productivity. The assay was tested as a means of monitoring the sizes of L. salivarius populations from broilers fed diets with different compositions, maintained at different stocking densities, or given the antimicrobial drugs bacitracin and monensin in the feed. Stocking densities did not influence the numbers of L. salivarius cells in the ileum. A diet containing meat and bone meal reduced the size of the L. salivarius population relative to that of chickens given the control diet, as did administration of bacitracin and monensin in the feed. These changes in the target bacterial population were associated with improved broiler weight gain. PMID:17890342

Antimicrobial Consumption in Medicated Feeds in Vietnamese Pig and Poultry Production.

PubMed

Van Cuong, Nguyen; Nhung, Nguyen Thi; Nghia, Nguyen Huu; Mai Hoa, Nguyen Thi; Trung, Nguyen Vinh; Thwaites, Guy; Carrique-Mas, Juan

2016-09-01

Antimicrobials are extensively used as growth promoters in animal feeds worldwide, but reliable estimates are lacking. We conducted an internet-based survey of commercial chicken and pig feed products officially approved for sale in Vietnam over the period March-June 2015. Information on the antimicrobial contents in feed products, alongside animal production data, was used to estimate in-feed antimicrobial consumption to produce one kilogram of live animal (chicken, pig), as well as to estimate country-wide antimicrobial consumption through animal feeds. A total of 1462 commercial feed formulations were examined. The survey-adjusted estimated antimicrobial contents were 25.7 and 62.3 mg/kg in chicken and pig feeds, respectively. Overall, it was estimated that 77.4 mg [95% CI 48.1-106.8] and 286.6 mg [95% CI 191.6-418.3] of in-feed antimicrobials were used to raise 1 kg of live chicken and pig, respectively. Bacitracin (15.5% feeds), chlortetracycline (11.4%), and enramycin (10.8%) were the most common antimicrobials present in chicken feed formulations, whereas bacitracin (24.8%), chlortetracycline (23.9%), and florfenicol (17.4%) were the most common in pig feed formulations. Overall, 57% of the total quantitative usage consisted of antimicrobials regarded by WHO of importance for human medicine, including amoxicillin, colistin, tetracyclines, neomycin, lincomycin, and bacitracin. These figures confirm a very high magnitude of in-feed consumption of antimicrobials, especially in pig production. Results from this study should encourage further monitoring of antimicrobials used in animal production, and foster discussion about existing policies on inclusion of antimicrobials in animal feed rations.

21 CFR 558.366 - Nicarbazin.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... It is used in chicken feed as follows: Nicarbazin in grams per ton Combination in grams per ton Indications for use Limitations Sponsor 27 to 45 Narasin 27 to 45 Broiler chickens; prevention of coccidiosis...)(1)(iii) 000986 Narasin 27 to 45 and bacitracin methylene disalicylate 4 to 50 Broiler chickens...

Outbreak of acute colitis on a horse farm associated with tetracycline-contaminated sweet feed.

PubMed Central

Keir, A A; Stämpfli, H R; Crawford, J

1999-01-01

Exposure of a group of horses to tetracycline-contaminated feed resulted in acute colitis and subsequent death in one horse and milder diarrhea in 3 others. The most severely affected animal demonstrated clinical and pathological findings typical of colitis X. The other herdmates responded well to administration of zinc bacitracin. PMID:10572668

21 CFR 558.550 - Salinomycin.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 60 grams of salinomycin activity per pound (as salinomycin sodium biomass). (b) Approvals. See...) Conditions of use. (1) Broilers: It is used as follows: (i)(a) Amount per ton. Salinomycin 40 to 60 grams. (b.... Salinomycin 40 to 60 grams and bacitracin methylene disalicylate 4 to 30 grams. (b) Indications for use. For...

Impact of Feed Supplementation with Antimicrobial Agents on Growth Performance of Broiler Chickens, Clostridium perfringens and Enterococcus Counts, and Antibiotic Resistance Phenotypes and Distribution of Antimicrobial Resistance Determinants in Escherichia coli Isolates▿

PubMed Central

Diarra, Moussa S.; Silversides, Fred G.; Diarrassouba, Fatoumata; Pritchard, Jane; Masson, Luke; Brousseau, Roland; Bonnet, Claudie; Delaquis, Pascal; Bach, Susan; Skura, Brent J.; Topp, Edward

2007-01-01

The effects of feed supplementation with the approved antimicrobial agents bambermycin, penicillin, salinomycin, and bacitracin or a combination of salinomycin plus bacitracin were evaluated for the incidence and distribution of antibiotic resistance in 197 commensal Escherichia coli isolates from broiler chickens over 35 days. All isolates showed some degree of multiple antibiotic resistance. Resistance to tetracycline (68.5%), amoxicillin (61.4%), ceftiofur (51.3%), spectinomycin (47.2%), and sulfonamides (42%) was most frequent. The levels of resistance to streptomycin, chloramphenicol, and gentamicin were 33.5, 35.5, and 25.3%, respectively. The overall resistance levels decreased from day 7 to day 35 (P < 0.001). Comparing treatments, the levels of resistance to ceftiofur, spectinomycin, and gentamicin (except for resistance to bacitracin treatment) were significantly higher in isolates from chickens receiving feed supplemented with salinomycin than from the other feeds (P < 0.001). Using a DNA microarray analysis capable of detecting commonly found antimicrobial resistance genes, we characterized 104 tetracycline-resistant E. coli isolates from 7- to 28-day-old chickens fed different growth promoters. Results showed a decrease in the incidence of isolates harboring tet(B), blaTEM, sulI, and aadA and class 1 integron from days 7 to 35 (P < 0.01). Of the 84 tetracycline-ceftiofur-resistant E. coli isolates, 76 (90.5%) were positive for blaCMY-2. The proportions of isolates positive for sulI, aadA, and integron class 1 were significantly higher in salinomycin-treated chickens than in the control or other treatment groups (P < 0.05). These data demonstrate that multiantibiotic-resistant E. coli isolates can be found in broiler chickens regardless of the antimicrobial growth promoters used. However, the phenotype and the distribution of resistance determinants in E. coli can be modulated by feed supplementation with some of the antimicrobial agents used in broiler

Use patterns, excretion masses and contamination profiles of antibiotics in a typical swine farm, south China.

PubMed

Zhou, Li-Jun; Ying, Guang-Guo; Zhang, Rui-Quan; Liu, Shan; Lai, Hua-Jie; Chen, Zhi-Feng; Yang, Bin; Zhao, Jian-Liang

2013-04-01

The objective of this study was to screen the occurrence of 50 antibiotics in a typical swine farm in southern China, which includes animal feeds, waste collection and treatment systems (lagoons and anaerobic digesters), and receiving environments (vegetable fields, streams, and private wells). Nine antibiotics were found in the feeds for different stages of the development of pigs in the swine farm, at concentrations ranging from 2.37 ± 0.16 ng g(-1) (sulfamethazine) to 61 500 ± 11 900 ng g(-1) (bacitracin). 11, 17 and 15 target compounds were detected in feces, flush water, and suspended particles in the swine farm, respectively. Based on the survey of feeds and animal waste from the farm, chlortetracycline, tetracycline, bacitracin and florfenicol in the feces, flush water and suspended particles mainly originated from the feeds, while most sulfonamides, including doxycycline, oxytetracycline, fluoroquinolones, macrolides and trimethoprim, were mainly from injection and other oral routes. The daily excretion masses of antibiotics per pig calculated based on animal waste had the following order: sows (48.3 mg per day per pig), piglets (18.9 mg per day per pig), growing pigs (7.01 mg per day per pig) and finishing pigs (1.47 mg per day per pig), indicating that the usage of antibiotics (type and dosage) and excretion masses are related to the growth stage of pigs. Chlortetracycline and bacitracin are the main contributors to the total excretion mass of antibiotics from pigs at different stages of development in the farm. The waste treatment system (lagoons and anaerobic digesters) was found to be ineffective in the elimination of antibiotics. The detection of some antibiotics in the surrounding environments of the farm (the well water, stream water and vegetable field soil) was a reflection of pollution from the swine farm.

Antimicrobial activity of topical agents against Propionibacterium acnes: an in vitro study of clinical isolates from a hospital in Shanghai, China.

PubMed

Ma, Ying; Zhang, Nanxue; Wu, Shi; Huang, Haihui; Cao, Yanpei

2016-12-01

This study aimed to compare the antimicrobial activities of topical agents against Propionibacterium acnes isolated from patients admitted to a hospital in Shanghai, China. The minimal inhibitory concentrations of the cultured P. acnes were determined in accordance with the Clinical and Laboratory Standards Institute. Susceptibilities to clindamycin and erythromycin were compared in terms of gender, age, disease duration, previous treatment, and disease severity. A total of 69 P. acnes strains were isolated from 98 patients (70.41%). The susceptibility to triple antibiotic ointment (neomycin/bacitracin/polymyxin B) and bacitracin was 100%. The susceptibility to fusidic acid was 92.7%. The resistance rates to neomycin sulfate, erythromycin, and clindamycin were 11.7%, 49.3%, and 33.4%, respectively. The high resistance rate to clindamycin and erythromycin was significantly affected by gender, previous treatment, and disease severity rather than by age and disease duration. Topical antibiotics should not be used separately for long-term therapy to avoid multiresistance. The use of topical antibiotics should be determined by clinicians on the basis of clinical conditions.

Antimicrobial susceptibility of Clostridium perfringens isolates of bovine, chicken, porcine, and turkey origin from Ontario.

PubMed

Slavić, Durđa; Boerlin, Patrick; Fabri, Marta; Klotins, Kim C; Zoethout, Jennifer K; Weir, Pat E; Bateman, Debbie

2011-04-01

Antimicrobial susceptibilities and toxin types were determined for 275 Clostridium perfringens isolates collected in Ontario in the spring of 2005. Minimal inhibitory concentrations (MICs) of C. perfringens isolates for 12 antimicrobials used in therapy, prophylaxis, and/or growth promotion of cattle (n = 40), swine (n = 75), turkeys (n = 50), and chickens (n = 100) were determined using the microbroth dilution method. Statistical analyses and MIC distributions showed reduced susceptibility to bacitracin, clindamycin, erythromycin, florfenicol, and tetracycline for some isolates. Reduced susceptibility to bacitracin was identified in chicken (64%) and turkey (60%) isolates. Swine isolates had predominantly reduced susceptibility to clindamycin (28%) and erythromycin (31%), whereas bovine isolates had reduced susceptibility to clindamycin (10%) and florfenicol (10%). Reduced susceptibility to tetracycline was spread across all species. No clear reduced susceptibility, but elevated MIC(50) for virginiamycin was found in chicken isolates in comparison with isolates from other species. Toxin typing revealed that C. perfringens type A is the dominant toxin type isolated in this study across all 4 host species.

Antimicrobial susceptibility of Clostridium perfringens isolates of bovine, chicken, porcine, and turkey origin from Ontario

PubMed Central

Slavić, Đurđa; Boerlin, Patrick; Fabri, Marta; Klotins, Kim C.; Zoethout, Jennifer K.; Weir, Pat E.; Bateman, Debbie

2011-01-01

Antimicrobial susceptibilities and toxin types were determined for 275 Clostridium perfringens isolates collected in Ontario in the spring of 2005. Minimal inhibitory concentrations (MICs) of C. perfringens isolates for 12 antimicrobials used in therapy, prophylaxis, and/or growth promotion of cattle (n = 40), swine (n = 75), turkeys (n = 50), and chickens (n = 100) were determined using the microbroth dilution method. Statistical analyses and MIC distributions showed reduced susceptibility to bacitracin, clindamycin, erythromycin, florfenicol, and tetracycline for some isolates. Reduced susceptibility to bacitracin was identified in chicken (64%) and turkey (60%) isolates. Swine isolates had predominantly reduced susceptibility to clindamycin (28%) and erythromycin (31%), whereas bovine isolates had reduced susceptibility to clindamycin (10%) and florfenicol (10%). Reduced susceptibility to tetracycline was spread across all species. No clear reduced susceptibility, but elevated MIC50 for virginiamycin was found in chicken isolates in comparison with isolates from other species. Toxin typing revealed that C. perfringens type A is the dominant toxin type isolated in this study across all 4 host species. PMID:21731178

Contraction of guinea-pig lung parenchymal strips by substance P and related peptides.

PubMed

Foreman, J C; Shelly, R; Webber, S E

1985-12-01

A dose-response relationship for substance P and contraction of the lung parenchyma strip of the guinea-pig could only be obtained in the presence of a mixture of bacitracin, 1,4 dithio-L-threitol and ethylenediamine tetracetic acid, all at 100 microM, or in the presence of captopril, 1.8 mM. Substance P (50 nM) caused no contraction by itself but produced a shift to the left of the dose-response curve for histamine with a mean dose-ratio of 1.4 +/- 0.2 (S.E. of mean). The peptides physalaemin, eledoisin and kassinin were all approximately equipotent with substance P on the lung strip, in the presence of peptides inhibitors. [D-Pro4, D-Trp7,9,10]-SP4-11, produced dose-related inhibition of the contraction induced by substance P. Substance P activity in guinea-pig lung declined exponentially with a half-time of 2.3 min: bacitracin, dithiothreitol and EDTA (all 100 microM) increased this to 7.2 min and captopril (1.8 mM) to 5.1 min.

21 CFR 558.175 - Clopidol.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Limitations Sponsor (1) 113.5 Broiler chickens and re-placement chickens intended for use as caged layers: As..., E. brunetti, and E. mivati Do not feed to chickens over 16 weeks of age 016592 (2) 113.5 Bacitracin methylene disalicylate 4 to 50 Broiler chickens: As in paragraph (d)(1) of this section; for increased rate...

21 CFR 558.555 - Semduramicin.

Code of Federal Regulations, 2010 CFR

2010-04-01

... tolerances. See § 556.597 of this chapter. (d) Conditions of use in chickens. It is used in chicken feed as... Sponsor (1) 22.7 (25 ppm) Broiler chickens: For the prevention of coccidiosis caused by Eimeria acervulina.... 066104 (2) 22.7 Bacitracin methylene disalicylate 10 to 50 Broiler chickens: As in paragraph (d)(1) of...

The Physiology, Biochemistry and Genetics of Survival of Bacteria Subjected to Environmental Stress

DTIC Science & Technology

1981-11-01

sodium lauryl sulfate , but not to sodtimnl chloride or streptomycin alone. This sensitivity was again transient and capable of... sodium lauryl sulfate but not to sodium chloride or streptomycin alone. This sensitivity was again transient and capable of repair in the name simple...polymyxin B, bacitracin, and sodium lauryl . - 19 sutfate during growth, to ethylenediaminetetraacetic acid and sodium lauryl AUTHOR: 20 sulfate in

21 CFR 558.175 - Clopidol.

Code of Federal Regulations, 2011 CFR

2011-04-01

... from the time chicks are placed in floor pens for 7 to 14 days 016592 (6) 113.5 Lincomycin 2 to 4... feed to chickens over 16 weeks of age; withdraw 5 days before slaughter; as sole source of organic..., E. brunetti, and E. mivati Do not feed to chickens over 16 weeks of age 016592 (2) 113.5 Bacitracin...

[Potentialization of antibiotics by lytic enzymes].

PubMed

Brisou, J; Babin, P; Babin, R

1975-01-01

Few lytic enzymes, specially papaine and lysozyme, acting on the membrane and cell wall structures facilitate effects of bacitracine, streptomycine and other antibiotics. Streptomycino resistant strains became sensibles to this antibiotic after contact with papaine and lysozyme. The results of tests in physiological suspensions concern only the lytic activity of enzymes. The results on nutrient medium concern together lytic, and antibiotic activities.

Requirement of the CroRS Two-Component System for Resistance to Cell Wall-Targeting Antimicrobials in Enterococcus faecium.

PubMed

Kellogg, Stephanie L; Little, Jaime L; Hoff, Jessica S; Kristich, Christopher J

2017-05-01

Enterococci are serious opportunistic pathogens that are resistant to many cell wall-targeting antibiotics. The CroRS two-component signaling system responds to antibiotic-mediated cell wall stress and is critical for resistance to cell wall-targeting antibiotics in Enterococcus faecalis Here, we identify and characterize an orthologous two-component system found in Enterococcus faecium that is functionally equivalent to the CroRS system of E. faecalis Deletion of croRS in E. faecium resulted in marked susceptibility to cell wall-targeting agents including cephalosporins and bacitracin, as well as moderate susceptibility to ampicillin and vancomycin. As in E. faecalis , exposure to bacitracin and vancomycin stimulates signaling through the CroRS system in E. faecium Moreover, the CroRS system is critical in E. faecium for enhanced beta-lactam resistance mediated by overexpression of Pbp5. Expression of a Pbp5 variant that confers enhanced beta-lactam resistance cannot overcome the requirement for CroRS function. Thus, the CroRS system is a conserved signaling system that responds to cell wall stress to promote intrinsic resistance to important cell wall-targeting antibiotics in clinically relevant enterococci. Copyright © 2017 American Society for Microbiology.

Requirement of the CroRS Two-Component System for Resistance to Cell Wall-Targeting Antimicrobials in Enterococcus faecium

PubMed Central

Kellogg, Stephanie L.; Little, Jaime L.; Hoff, Jessica S.

2017-01-01

ABSTRACT Enterococci are serious opportunistic pathogens that are resistant to many cell wall-targeting antibiotics. The CroRS two-component signaling system responds to antibiotic-mediated cell wall stress and is critical for resistance to cell wall-targeting antibiotics in Enterococcus faecalis. Here, we identify and characterize an orthologous two-component system found in Enterococcus faecium that is functionally equivalent to the CroRS system of E. faecalis. Deletion of croRS in E. faecium resulted in marked susceptibility to cell wall-targeting agents including cephalosporins and bacitracin, as well as moderate susceptibility to ampicillin and vancomycin. As in E. faecalis, exposure to bacitracin and vancomycin stimulates signaling through the CroRS system in E. faecium. Moreover, the CroRS system is critical in E. faecium for enhanced beta-lactam resistance mediated by overexpression of Pbp5. Expression of a Pbp5 variant that confers enhanced beta-lactam resistance cannot overcome the requirement for CroRS function. Thus, the CroRS system is a conserved signaling system that responds to cell wall stress to promote intrinsic resistance to important cell wall-targeting antibiotics in clinically relevant enterococci. PMID:28223383

Epizootic rabbit enteropathy inoculum (TEC4): antibiograms and antibiotic fractionation.

PubMed

Huybens, Nathalie; Houeix, Julien; Licois, Dominique; Mainil, Jacques; Marlier, Didier

2011-01-01

Epizootic rabbit enteropathy (ERE) emerged and spread in Europe within the last 13 years causing major economical loss. The aims of the study was to evaluate antibiograms of TEC4, an inoculum composed of an extract of intestinal content of affected rabbits, and to test the potential of different antibiotic-based TEC4 fractions to reproduce the disease. Twenty nine different antibiotic discs were incubated for determining bacteria resistance. In a complementary study, nine tubes of liquid medium were inoculated with TEC4, incubated and added individually with amoxicillin/clavulanic acid, bacitracin, ceftiofur, doxycycline, novobiocin, streptomycyin, tylosin, vancomycin and 0.9% saline solution as control. The content of each tube was washed by centrifugation and suspended in saline. The three most effective antibiotics are florfenicol, amoxycillin/clavulanic acid and tylosin. A high concentration of Clostridium sordelli and Bacillus firmus were isolated in all fractions. Species never cultured from TEC4 were identified as Fusobacterium necrogenes (in vancomycin fraction), Cellulomonas sp (in novobiocin fraction) and Bacteroides distasonis (in doxycycline fraction). The ERE was reproduced when bacitracin, doxycycline and 0.9% fractions were inoculated. Rabbits showed ERE clinical signs with the specific drop in daily weight gain.

Comparison of Irrigation Solutions and Devices in a Contaminated Musculoskeletal Wound Survival Model

DTIC Science & Technology

2009-01-01

greatest reduction was seen with castile soap, which lowered the photon count to 13% of the pretreatment level. This was followed by benzalkonium chloride ...castile soap was significantly greater than that with the normal saline solution (p = 0.0069), while the reductions with benzalkonium chloride (p...the goats were assigned to four treatment groups: normal saline solution, bacitracin solution, castile soap, and benzalkonium chloride . All wounds

Bacillus subtilis and yeast cell wall improve the intestinal health of broilers challenged by Clostridium perfringens.

PubMed

Li, Z; Wang, W; Lv, Z; Liu, D; Guo, Y

2017-12-01

1. The objective was to investigate the effects of Bacillus subtilis, yeast cell wall (YCW) and their combination on intestinal health of broilers challenged by Clostridium perfringens over a 21-d period. 2. Using a 5 × 2 factorial arrangement of treatments, 800 1-d-old male Cobb 500 broilers were used to study the effects of feed additives (without additive or with zinc bacitracin, B. subtilis, YCW, and the combination of B. subtilis and YCW), pathogen challenge (without or with Clostridium perfringens challenge), and their interactive effects. 3. C. perfringens infection increased intestinal lesions scores, damaged intestinal histomorphology, increased serum endotoxin concentration, cytokine mRNA expression and intestinal population of C. perfringens and Escherichia coli and decreased ileal bifidobacteria numbers. The 4 additives decreased serum endotoxin. Zinc bacitracin tended to decrease cytokine mRNA expression and the intestinal number of C. perfringens and E. coli. B. subtilis, YCW and their combination increased cytokine mRNA expression. B. subtilis and YCW decreased the number of C. perfringens and E. coli in the ileum, and their combination decreased pathogens numbers in the ileum and caecum. 4. In conclusion, B. subtilis, YCW and their combination improved the intestinal health of NE-infected broilers, and could be potential alternatives to antibiotics.

Protease inhibitors and indoleamines selectively inhibit cholinesterases in the histopathologic structures of Alzheimer disease.

PubMed Central

Wright, C I; Guela, C; Mesulam, M M

1993-01-01

Neurofibrillary tangles and amyloid plaques express acetylcholinesterase and butyrylcholinesterase activity in Alzheimer disease. We previously reported that traditional acetylcholinesterase inhibitors such as BW284C51, tacrine, and physostigmine were more potent inhibitors of the acetylcholinesterase in normal axons and cell bodies than of the acetylcholinesterase in plaques and tangles. We now report that the reverse pattern is seen with indoleamines (such as serotonin and its precursor 5-hydroxytryptophan), carboxypeptidase inhibitor, and the nonspecific protease inhibitor bacitracin. These substances are more potent inhibitors of the cholinesterases in plaques and tangles than of those in normal axons and cell bodies. These results show that the enzymatic properties of plaque and tangle-associated cholinesterases diverge from those of normal axons and cell bodies. The selective susceptibility to bacitracin and carboxypeptidase inhibitor indicates that the catalytic sites of plaque and tangle-bound cholinesterases are more closely associated with peptidase or protease-like properties than the catalytic sites of cholinesterases in normal axons and cell bodies. This shift in enzymatic affinity may lead to the abnormal protein processing that is thought to play a major role in the pathogenesis of Alzheimer disease. The availability of pharmacological and dietary means for altering brain indoleamines raises therapeutic possibilities for inhibiting the abnormal cholinesterase activity associated with Alzheimer disease. Images PMID:8421706

Biosynthesis of Enterobacterial Common Antigen: The ECA-Trace Phenotype of Salmonella Typhimurium and The Role of the rfe Gene in 08 Side-Chain Synthesis in Escherichia Coli

DTIC Science & Technology

1993-03-18

malachite green, 2mg/ml; erythromycin, 2mg/ml; bacitracin, 20mg/ml; streptomycin, 50mg/ml; crystal violet, 100mg/ml; novobiocin, Smg/ml; rifamycin...cephalosporin C, ISug/ml; actinomycin D, 37Sug/ml; kanamycin, S.6ug/ml; chlorotetracycline, 3.8ug/ml; vancomycin, 900ug/ml; malachite green, 60ug...carbenicillin; Ceph, cephalosporin C; AcID, actinomycin D; ((an, kanamycin; Ctet, chlorotetracycline; Van, vancomycin; MalG, malachite green; Eryth

Comparison of irrigation solutions and devices in a contaminated musculoskeletal wound survival model.

PubMed

Owens, Brett D; White, Daniel W; Wenke, Joseph C

2009-01-01

There is much to learn about the effectiveness of different methods currently used for the irrigation of open wounds. The purpose of this study was to compare various approaches in a survival animal model. We used an established goat model involving the creation of a reproducible complex musculoskeletal wound followed by inoculation with Pseudomonas aeruginosa (lux) bacteria. This genetically altered luminescent bacterium provides the ability for quantitative analysis with a photon-counting camera system. For Study 1, wound irrigation was performed six hours after the injury and inoculation; the goats were assigned to four treatment groups: normal saline solution, bacitracin solution, castile soap, and benzalkonium chloride. All wounds received sharp débridement and irrigation with use of a pulsatile lavage device (19 psi). Images and photon counts were obtained prior to irrigation, after irrigation, and forty-eight hours after injury and inoculation. For Study 2, we used the same animal model and compared bulb syringe and pulsatile lavage irrigation with saline solution. In Study 1, the irrigation treatment lowered the bacterial counts in all treatment groups. The greatest reduction was seen with castile soap, which lowered the photon count to 13% of the pretreatment level. This was followed by benzalkonium chloride, bacitracin, and saline solution at 18%, 22%, and 29%, respectively. At forty-eight hours, imaging showed a rebound in bacterial counts in every group. The highest rebound was measured in the castile soap group, which rebounded to 120% of the pretreatment level. The benzalkonium chloride group experienced a rebound to 94% of the pretreatment level. These were followed by bacitracin solution (89%) and normal saline solution (68%). In Study 2, both treatment methods were effective in removing 75% of the bacteria initially. At forty-eight hours, the bacterial levels in the pulsed lavage group rebounded to 94% of the original levels (compared with 48% in

Pretreatment of pericardial patches with antibiotics does not alter patch healing in vivo.

PubMed

Bai, Hualong; Kuwahara, Go; Wang, Mo; Brownson, Kirstyn E; Foster, Trenton R; Yamamoto, Kota; Xing, Ying; Dardik, Alan

2016-04-01

Pretreatment with antibiotics is commonly performed before surgical implantation of prosthetic materials. We previously showed that pericardial patches are infiltrated by macrophages and arterial stem cells after implantation into an artery. We hypothesized that antibiotic pretreatment would diminish the number of cells infiltrating into the patch, potentially affecting early neointimal formation. Bovine pericardial patches were pretreated with saline, bacitracin (500 U/mL), or cephalexin (10 mg/mL) for 30 minutes before implantation into the Wistar rat infrarenal aorta. Patches were retrieved on day 7 or day 30 and analyzed for histology and cell infiltration. Markers of proliferation, apoptosis, vascular cell identity, and M1 and M2 macrophage subtypes were examined using immunofluorescence and immunohistochemistry. Extracted proteins were analyzed by Western blot. At day 7, pericardial patches pretreated with bacitracin or cephalexin showed similar amounts of neointimal thickening (P = .55) and cellular infiltration (P = .42) compared with control patches. Patches pretreated with antibiotics showed similar proliferation (P = .09) and apoptosis (P = .84) as control patches. The cell composition of the neointima in pretreated patches was similar to control patches, with a thin endothelial layer overlying a thin layer of smooth muscle cells (P = .45), and containing similar numbers of CD34-positive (P = .26) and vascular endothelial growth factor receptor 2-positive (P = .31) cells. Interestingly, within the body of the patch, there were fewer macrophages (P = .0003) and a trend towards fewer endothelial progenitor cells (P = .051). No M1 macrophages were found in or around any of the patches. M2 macrophages were present around the patches, and there was no difference in numbers of M2 macrophages surrounding control patches and patches pretreated with antibiotics (P = .24). There was no difference in neointimal thickness at day 30 between control

Presence and characterization of Campylobacter jejuni in organically raised chickens in Quebec

PubMed Central

Thibodeau, Alexandre; Fravalo, Philippe; Laurent-Lewandowski, Sylvette; Guévremont, Evelyne; Quessy, Sylvain; Letellier, Ann

2011-01-01

The objective of this study was to estimate the presence of the important foodborne pathogen Campylobacter jejuni in organically raised chickens in the province of Quebec. The recovered isolates were further characterized for their antimicrobial resistance profile, autoagglutination property and chemotaxis. Antimicrobial resistance was evaluated using agar dilution for: tetracycline, erythromycin, chloramphenicol, ciprofloxacin, gentamicin, nalidixic acid, clindamycin, ampicillin, azithromycin, bacitracin, and ceftiofur. Autoagglutination was measured by monitoring optical density changes in a bacterial suspension after 3 h of incubation at room temperature. Chemotaxis was evaluated after a contact time of 3 h between isolates and mucin, using a quantitative protocol. A total of 10 lots of chickens was sampled in August and September 2009; half of them were positive for the presence of C. jejuni. Antimicrobial resistance was found only for tetracycline (44%), erythromycin (6%), azithromycin (6%) and clindamycin (2%). Variation was observed in the minimum inhibitory concentrations (MICs) for ceftiofur and bacitracin, for which C. jejuni possess intrinsic resistance. Autoagglutination and chemotaxis varied among isolates and lot-level differences in these were observed. Autoagglutination and chemotaxis levels appeared as independent isolate properties. Further monitoring and characterization of isolates originating from organic chickens is of interest since this type of production might represent another source of exposure of consumers to a variety of the foodborne pathogen C. jejuni. PMID:22468028

21 CFR 524.154 - Bacitracin, neomycin, and polymyxin B ophthalmic ointment.

Code of Federal Regulations, 2014 CFR

2014-04-01

... paragraph (c) of this section. (c) Conditions of use in dogs and cats.—(1) Amount. Apply a thin film over... 10,000 units of polymyxin B sulfate. (b) Sponsors. See sponsor numbers in § 510.600(c) of this chapter as follows: (1) No. 054771 for use of product described in paragraph (a)(1) as in paragraph (c) of...

Biogenic nanoparticles bearing antibacterial activity and their synergistic effect with broad spectrum antibiotics: Emerging strategy to combat drug resistant pathogens.

PubMed

Baker, Syed; Pasha, Azmath; Satish, Sreedharamurthy

2017-01-01

The present study emphasizes on synthesis of bimetallic silver-gold nanoparticles from cell free supernatant of Pseudomonas veronii strain AS41G inhabiting Annona squamosa L. The synthesized nanoparticles were characterized using hyphenated techniques with UV-Visible spectra ascertained absorbance peak between 400 and 800 nm. Possible interaction of biomolecules in mediating and stabilization of nanoparticles was depicted with Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) displayed Bragg's peak conferring the 1 0 0, 1 1 1, 2 0 0, and 2 2 0 facets of the face centered cubic symmetry of nanoparticles suggesting that these nanoparticles were crystalline in nature. Size and shape of the nanoparticles were determined using Transmission electron microscopy (TEM) microgram with size ranging from 5 to 50 nm forming myriad shapes. Antibacterial activity of nanoparticles against significant human pathogens was conferred with well diffusion assay and its synergistic effect with standard antibiotics revealed 87.5% fold increased activity with antibiotic "bacitracin" against bacitracin resistant strains Bacillus subtilis , Escherichia coli and Klebsiella pneumoniae followed by kanamycin with 18.5%, gentamicin with 11.15%, streptomycin with 10%, erythromycin with 9.7% and chloramphenicol with 9.4%. Thus the study concludes with biogenic and ecofriendly route for synthesizing nanoparticles with antibacterial activity against drug resistant pathogens and attributes growing interest on endophytes as an emerging source for synthesis of nanoparticles.

Randomized clinical trial comparing ceftiofur hydrochloride with a positive control protocol for intramammary treatment of nonsevere clinical mastitis in dairy cows.

PubMed

Cortinhas, Cristina Simões; Tomazi, Tiago; Zoni, Mário Sérgio Ferreira; Moro, Elio; Veiga Dos Santos, Marcos

2016-07-01

The objective of this study was to compare ceftiofur hydrochloride with a positive control protocol for intramammary treatment of nonsevere clinical mastitis in dairy cows. A total of 264 clinical mastitis cases on 11 commercial dairy farms were treated with intramammary infusions, once a day for 4 d using 1 of 2 treatments: (1) ceftiofur hydrochloride 125mg; or (2) control: tetracycline 200mg + neomycin 250mg + bacitracin 28mg + prednisolone 10mg. Streptococcus agalactiae was the most frequently isolated gram-positive pathogen from clinical mastitis, followed by Staphylococcus aureus. Klebsiella spp. and Escherichia coli were the most isolated gram-negative bacteria from clinical mastitis. No significant differences were observed between treatments regarding the overall clinical cure, bacteriological cure, and new infection. No effect of treatment regimen was observed when the bacterial group (gram-positive vs. gram-negative) was evaluated. The overall clinical cure was 0.79 for ceftiofur-treated cows and 0.74 for control-treated cows, whereas the overall bacteriological cure was 0.79 for ceftiofur-treated cows and 0.76 for control-treated cows. Furthermore, the new intramammary infection was 0.10 for cows treated with ceftiofur and 0.11 for cows treated with control. In conclusion, the use of intramammary ceftiofur hydrochloride for treatment of nonsevere clinical mastitis has similar efficacy as a treatment regimen with a combination of antimicrobial agents (tetracycline + neomycin + bacitracin). Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Genome-wide dynamics of a bacterial response to antibiotics that target the cell envelope

PubMed Central

2011-01-01

Background A decline in the discovery of new antibacterial drugs, coupled with a persistent rise in the occurrence of drug-resistant bacteria, has highlighted antibiotics as a diminishing resource. The future development of new drugs with novel antibacterial activities requires a detailed understanding of adaptive responses to existing compounds. This study uses Streptomyces coelicolor A3(2) as a model system to determine the genome-wide transcriptional response following exposure to three antibiotics (vancomycin, moenomycin A and bacitracin) that target distinct stages of cell wall biosynthesis. Results A generalised response to all three antibiotics was identified which involves activation of transcription of the cell envelope stress sigma factor σE, together with elements of the stringent response, and of the heat, osmotic and oxidative stress regulons. Attenuation of this system by deletion of genes encoding the osmotic stress sigma factor σB or the ppGpp synthetase RelA reduced resistance to both vancomycin and bacitracin. Many antibiotic-specific transcriptional changes were identified, representing cellular processes potentially important for tolerance to each antibiotic. Sensitivity studies using mutants constructed on the basis of the transcriptome profiling confirmed a role for several such genes in antibiotic resistance, validating the usefulness of the approach. Conclusions Antibiotic inhibition of bacterial cell wall biosynthesis induces both common and compound-specific transcriptional responses. Both can be exploited to increase antibiotic susceptibility. Regulatory networks known to govern responses to environmental and nutritional stresses are also at the core of the common antibiotic response, and likely help cells survive until any specific resistance mechanisms are fully functional. PMID:21569315

76 FR 53050 - New Animal Drugs; Ampicillin Trihydrate, Bacitracin Methylene Disalicylate, Flunixin...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-25

... trihydrate. * * * * * (d) * * * (2) * * * (iii) Limitations. Do not treat cattle for more than 7 days. Milk from treated cows must not be used for food during treatment and for 48 hours (4 milkings) after the...

21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Conditions of use in dogs(1) Amount. Administer 1 level teaspoonful per 10 pounds of body weight three times... diarrhea. (3) Limitations. Federal law restricts this drug to use by or on the order of a licensed...

21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Conditions of use in dogs—(1) Amount. Administer 1 level teaspoonful per 10 pounds of body weight three times... diarrhea. (3) Limitations. Federal law restricts this drug to use by or on the order of a licensed...

21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Conditions of use in dogs—(1) Amount. Administer 1 level teaspoonful per 10 pounds of body weight three times... diarrhea. (3) Limitations. Federal law restricts this drug to use by or on the order of a licensed...

21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Conditions of use in dogs—(1) Amount. Administer 1 level teaspoonful per 10 pounds of body weight three times... diarrhea. (3) Limitations. Federal law restricts this drug to use by or on the order of a licensed...

21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Conditions of use in dogs—(1) Amount. Administer 1 level teaspoonful per 10 pounds of body weight three times... diarrhea. (3) Limitations. Federal law restricts this drug to use by or on the order of a licensed...

Production, secretion, and stability of human secreted alkaline phosphatase in tobacco NT1 cell suspension cultures.

PubMed

Becerra-Arteaga, Alejandro; Mason, Hugh S; Shuler, Michael L

2006-01-01

Tobacco NT1 cell suspension cultures secreting active human secreted alkaline phosphatase (SEAP) were generated for the first time as a model system to study recombinant protein production, secretion, and stability in plant cell cultures. The SEAP gene encodes a secreted form of the human placental alkaline phosphatase (PLAP). During batch culture, the highest level of active SEAP in the culture medium (0.4 U/mL, corresponding to approximately 27 mg/L) was observed at the end of the exponential growth phase. Although the level of active SEAP decreased during the stationary phase, the activity loss did not appear to be due to SEAP degradation (based on Western blots) but due to SEAP denaturation. The protein-stabilizing agents polyvinylpirrolidone (PVP) and bacitracin were added extracellularly to test for their ability to reduce the loss of SEAP activity during the stationary phase. Bacitracin (100 mg/L) was the most effective treatment at sustaining activity levels for up to 17 days post-subculture. Commercially available human placental alkaline phosphatase (PLAP) was used to probe the mechanism of SEAP deactivation. Experiments with PLAP in sterile and conditioned medium corroborated the denaturation of SEAP by factors generated by cell growth and not due to simple proteolysis. We also show for the first time that the factors promoting activity loss are heat labile at 95 degrees C but not at 70 degrees C, and they are not inactivated after a 5 day incubation period under normal culture conditions (27 degrees C). In addition, there were no significant changes in pH or redox potential when comparing sterile and cell-free conditioned medium during PLAP incubation, indicating that these factors were unimportant.

PrkC-mediated phosphorylation of overexpressed YvcK protein regulates PBP1 protein localization in Bacillus subtilis mreB mutant cells.

PubMed

Foulquier, Elodie; Pompeo, Frédérique; Freton, Céline; Cordier, Baptiste; Grangeasse, Christophe; Galinier, Anne

2014-08-22

The YvcK protein has been shown to be necessary for growth under gluconeogenic conditions in Bacillus subtilis. Amazingly, its overproduction rescues growth and morphology defects of the actin-like protein MreB deletion mutant by restoration of PBP1 localization. In this work, we observed that YvcK was phosphorylated at Thr-304 by the protein kinase PrkC and that phosphorylated YvcK was dephosphorylated by the cognate phosphatase PrpC. We show that neither substitution of this threonine with a constitutively phosphorylated mimicking glutamic acid residue or a phosphorylation-dead mimicking alanine residue nor deletion of prkC or prpC altered the ability of B. subtilis to grow under gluconeogenic conditions. However, we observed that a prpC mutant and a yvcK mutant were more sensitive to bacitracin compared with the WT strain. In addition, the bacitracin sensitivity of strains in which YvcK Thr-304 was replaced with either an alanine or a glutamic acid residue was also affected. We also analyzed rescue of the mreB mutant strain by overproduction of YvcK in which the phosphorylation site was substituted. We show that YvcK T304A overproduction did not rescue the mreB mutant aberrant morphology due to PBP1 mislocalization. The same observation was made in an mreB prkC double mutant overproducing YvcK. Altogether, these data show that YvcK may have two distinct functions: 1) in carbon source utilization independent of its phosphorylation level and 2) in cell wall biosynthesis and morphogenesis through its phosphorylation state. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Drug use and antimicrobial resistance among Escherichia coli and Enterococcus spp. isolates from chicken and turkey flocks slaughtered in Quebec, Canada

PubMed Central

Boulianne, Martine; Arsenault, Julie; Daignault, Danielle; Archambault, Marie; Letellier, Ann; Dutil, Lucie

2016-01-01

An observational study was conducted of chicken and turkey flocks slaughtered at federal processing plants in the province of Quebec, Canada. The objectives were to estimate prevalence of drug use at hatchery and on farm and to identify antimicrobial resistance (AMR) in cecal Escherichia coli and Enterococcus spp. isolates and factors associated with AMR. Eighty-two chicken flocks and 59 turkey flocks were sampled. At the hatchery, the most used antimicrobial was ceftiofur in chickens (76% of flocks) and spectinomycin in turkeys (42% of flocks). Virginiamycin was the antimicrobial most frequently added to the feed in both chicken and turkey flocks. At least 1 E. coli isolate resistant to third-generation cephalosporins was present in all chicken flocks and in a third of turkey flocks. Resistance to tetracycline, streptomycin, and sulfisoxazole was detected in > 90% of flocks for E. coli isolates. Antimicrobial resistance (AMR) was observed to bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, and tetracycline in both chicken and turkey flocks for Enterococcus spp. isolates. No resistance to vancomycin was observed. The use of ceftiofur at hatchery was significantly associated with the proportion of ceftiofur-resistant E. coli isolates in chicken flocks. In turkey flocks, ceftiofur resistance was more frequent when turkeys were placed on litter previously used by chickens. Associations between drug use and resistance were observed with tetracycline (turkey) in E. coli isolates and with bacitracin (chicken and turkey), gentamicin (turkey), and tylosin (chicken) in Enterococcus spp. isolates. Further studies are needed to provide producers and veterinarians with alternative management practices and tools in order to reduce the use of antimicrobial feed additives in poultry. PMID:26733732

Hydrolyzable and condensed tannins resistance in Clostridium perfringens.

PubMed

Redondo, L M; Dominguez, J E; Rabinovitz, B C; Redondo, E A; Fernández Miyakawa, M E

2015-08-01

Tannins added in the diet are being used to improve nutrition and health in farm animals as an alternative to antibiotic growth promoters and to control enteric clostridial diseases. However, the capacity of Clostridium perfringens to develop resistance under the selective pressure of tannins is unknown. The purpose of this study was to determine if C. perfringens possess the ability to develop resistance against tannins in comparison with antimicrobial agents. Susceptibility for 7 AGPs (antimicrobial growth promoters), 9 therapeutic antimicrobials and 2 tannin based extracts was determined for 30 C. perfringens strains isolated from poultry and cattle. Two susceptible strains were selected and cultured in presence of sub-inhibitory concentrations of tannins and AGPs for resistant sub-populations selection. Tannin resistance of C. perfringens isolates from both animal species revealed no statistically significant differences in MICs (minimum inhibitory concentration). Poultry isolates showed higher MICs to several AGPs compared with cattle isolates. All isolates were susceptible to the therapeutic antimicrobials tested, but avian isolates showed a significantly lower susceptibility to these antimicrobials which was highly correlated with an increased resistance to bacitracin and others AGPs. In-vitro selection of resistant clones suggests that C. perfringens was unable to develop resistance against tannins at least compared to AGPs like bacitracin and avilamycin. Avian origin strains, which were previously exposed to antibiotics showed higher resistance, compared to cattle origin strains. These results suggest that the evolution of resistance against tannins in C. perfringens would be more difficult and slower than to the determined AGPs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Drug use and antimicrobial resistance among Escherichia coli and Enterococcus spp. isolates from chicken and turkey flocks slaughtered in Quebec, Canada.

PubMed

Boulianne, Martine; Arsenault, Julie; Daignault, Danielle; Archambault, Marie; Letellier, Ann; Dutil, Lucie

2016-01-01

An observational study was conducted of chicken and turkey flocks slaughtered at federal processing plants in the province of Quebec, Canada. The objectives were to estimate prevalence of drug use at hatchery and on farm and to identify antimicrobial resistance (AMR) in cecal Escherichia coli and Enterococcus spp. isolates and factors associated with AMR. Eighty-two chicken flocks and 59 turkey flocks were sampled. At the hatchery, the most used antimicrobial was ceftiofur in chickens (76% of flocks) and spectinomycin in turkeys (42% of flocks). Virginiamycin was the antimicrobial most frequently added to the feed in both chicken and turkey flocks. At least 1 E. coli isolate resistant to third-generation cephalosporins was present in all chicken flocks and in a third of turkey flocks. Resistance to tetracycline, streptomycin, and sulfisoxazole was detected in > 90% of flocks for E. coli isolates. Antimicrobial resistance (AMR) was observed to bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, and tetracycline in both chicken and turkey flocks for Enterococcus spp. isolates. No resistance to vancomycin was observed. The use of ceftiofur at hatchery was significantly associated with the proportion of ceftiofur-resistant E. coli isolates in chicken flocks. In turkey flocks, ceftiofur resistance was more frequent when turkeys were placed on litter previously used by chickens. Associations between drug use and resistance were observed with tetracycline (turkey) in E. coli isolates and with bacitracin (chicken and turkey), gentamicin (turkey), and tylosin (chicken) in Enterococcus spp. isolates. Further studies are needed to provide producers and veterinarians with alternative management practices and tools in order to reduce the use of antimicrobial feed additives in poultry.

Illumina Miseq platform analysis caecum bacterial communities of rex rabbits fed with different antibiotics.

PubMed

Zou, Fuqin; Zeng, Dong; Wen, Bin; Sun, Hao; Zhou, Yi; Yang, Mingyue; Peng, Zhirong; Xu, Shuai; Wang, Hesong; Fu, Xiangchao; Du, Dan; Zeng, Yan; Zhu, Hui; Pan, Kangcheng; Jing, Bo; Wang, Ping; Ni, Xueqin

2016-12-01

Antibiotics have been widely used for the prevention and the treatment of diseases to humans and animals, and they have fed additives for agricultural animals to promote growth. However, there is a growing concern over the practice due to its side effects on intestinal microbial communities which plays a vital role in animals' health. To investigate the effect of antibiotics on the bacterial population of the caecum in rex rabbits, 80 rex rabbits were randomly divided into four groups: control group (B, basal diet), chlortetracycline group (C, 50 mg/kg), colistin sulfate group (S, 20 mg/kg) and zinc bacitracin group (Z, 40 mg/kg). Caecum microbial communities of rex rabbits from the four groups were analyzed through Illumina Miseq platform after being fed 28 days. The results showed that most obtained sequences belongs to Firmicutes followed by Bacteroidetes, and the ratio of Bacteroidetes/Firmicutes in C group (42.31 %) was higher than that in Z group (21.84 %). Zinc bacitracin supplementation caused a significant decreased of the Proteobacteria phylum and Lactobacillus spp. (P < 0.05), while the Lactobacillus spp. significantly increased in S group (P < 0.05). In addition, Ruminococcus spp., especially Ruminococcus albus were the predominant bacterial species found in both S and Z groups. The proportion of Coprococcus spp. significantly increased in Z group (P < 0.05). These findings suggested that the antibiotics used may cause significant changes in the caecum microbiota of rex rabbits, and we also found C group had a similarity caecum bacteria structure with B group which was probably due to the high levels of chlortetracycline resistance.

Antimicrobial susceptibility of Clostridium perfringens strains isolated from broiler chickens

PubMed Central

Silva, R. O. S.; Salvarani, F.M.; Assis, R.A.; Martins, N.R.S.; Pires, P.S.; Lobato, F.C.F.

2009-01-01

Clostridium perfringens is a normal inhabitant of the intestinal tract of chickens as well as a potential pathogen that causes necrotic enteritis and colangio hepatitis. The minimum inhibitory concentration (MIC) of seven different compounds used for therapy, growth promotion or prevention of coccidiosis was determined by agar dilution method for 55 C. perfringens strains isolated from the intestines of broiler chickens. All strains showed high susceptibility to penicillin, avilamycin, monensin and narasin. Only 7.3% of the strains showed an intermediated sensitivity to lincomycin, and 49 (89.1%) were considered susceptible. For tetracycline and bacitracin, 41.8% and 47.3% of strains, respectively, were considered resistant. PMID:24031355

[Antibiotic resistance of Campylobacter and its epidemiologic significance].

PubMed

Aleksandrova, N Z; Minaev, V I; Gorelov, A V

1990-03-01

Sensitivity of 179 strains of thermophilic Campylobacter to 21 chemotherapeutic drugs was studied. Activity of the antibacterial agents against the pathogens was estimated by the MICs. The MIC50 and MIC90 were also determined. All the Campylobacter strains were sensitive to gentamicin, chloramphenicol, neomycin, furazolidone and furagin and resistant to cefazolin, polymyxin E, rifampicin, vancomycin and bacitracin. Differences in the attitude of the Campylobacter isolates from various sources and patients of various age groups to the chemotherapeutic drugs were detected. Possible consideration of the results of comparison of R spectra of Campylobacter strains and the levels of their resistance to antimicrobial drugs as epidemiological markers is discussed.

[Clinical studies on Frubienzyme in a controlled double-blind trial].

PubMed

Raus, I

1976-10-07

In a controlled clinical trial Frubienzym (throat lozenges with 5 mg lysozyme, 2 mg papaine and 200 I.U. bacitracin) or placebo have been given to 100 patients with pharyngitis and/or tonsillitis for 4 days. Under treatment with Frubienzym reddening, swelling, matter and mucus in the throat, coughing, swelling and pain of lymphatic ganglions and pain of swallowing vanished more quickly than under placebo. The differences were significant (p less than 0,05, p less than 0,001 or even p less than 0,001; U-test of Wilcoxon, Man and Whitney). There were no side effects which could be attributed to Frubienzym.

Antibiotic Sensitivity of Micrococcus radiodurans

PubMed Central

Hawiger, J.; Jeljaszewicz, J.

1967-01-01

A wild-type strain of Micrococcus radiodurans and its nonpigmented mutant W1 were tested for sensitivity to 10 antibiotics selected from the standpoint of their mechanism of action. Representatives of groups of antibiotics inhibiting deoxyribonucleic acid (DNA) synthesis, DNA-dependent ribonucleic acid synthesis, protein synthesis, and cell wall synthesis were selected. M. radiodurans and its mutant exhibited full susceptibility to all antibiotics tested (mitomycin C, actinomycin D, chloramphenicol, dihydrostreptomycin, erythromycin, neomycin, kanamycin, benzylpenicillin, bacitracin, and vancomycin), the degree of susceptibility being of the same order as that of a standard strain of Staphylococcus aureus 209 P, with the exception of dihydrostreptomycin. PMID:4166078

Combination of antibiotics suppressed the increase of a part of ARGs in fecal microorganism of weaned pigs.

PubMed

Li, Huizhi; Chu, Qingpo; Xu, Feilong; Fu, Lingling; Liang, Tingting; Li, Yuan; Zhou, Bo

2016-09-01

The presence of antibiotic resistance genes (ARGs) is one of the most important public health concerns. Six tetracycline resistance genes (TRGs-tetA, tetC, tetL, tetO, tetW, and tetX) were quantified using real-time quantitative polymerase chain reaction (qPCR) in the fecal microorganisms of weaned pigs. Two hundred 35-day-old weaned pigs were fed different dietary antibiotics for 28 days: (1) no antibiotic as the control treatment (CT); (2) chlortetracycline, bacitracin zinc and colistin sulfate (CBC); (3) bacitracin zinc and colistin sulfate (BC); and (4) chlortetracycline (CTC). The detection frequencies (DFs) of tetC, tetL, and tetW were 100 %; and the DFs of tetA, tetD, tetM, tetO, and tetX were 65 %. The relative abundances (tet/16S rRNA gene copy numbers) of six tet genes (tetA, tetC, tetL, tetO, tetW and tetX) were between 1.5 × 10(-4) and 2.0 × 10(-1). In the group CTC, the relative abundances of tetC (P < 0.01), tetL (P < 0.01), tetO (P < 0.05), tetW (P < 0.01), and tetX (P < 0.01) were greater than those of the group CT. Compared with the group CTC, the relative abundances of tetC (P < 0.01), tetL (P < 0.01), and tetW (P < 0.01) were decreased in the CBC and BC groups. These results indicate that a combination of different antibiotics suppressed the abundance increase of a part of tet genes, which suggests that a combination of antibiotics produces multiple selection pressures on fecal microorganism of pigs.

Effects of Dietary Additives and Early Feeding on Performance, Gut Development and Immune Status of Broiler Chickens Challenged with Clostridium perfringens

PubMed Central

Ao, Z.; Kocher, A.; Choct, M.

2012-01-01

The effects of dietary additives and holding time on resistance and resilience of broiler chickens to Clostridium perfringens challenge were investigated by offering four dietary treatments. These were a negative control (basal), a positive control (Zn-bacitracin) and two dietary additives, mannanoligosaccharides (MOS), and acidifier. Two holding times included (a) immediate access to feed and water post hatch (FED) and (b) access to both feed and water 48 h post hatch (HELD). Chicks fed Zn-bacitracin had no intestinal lesions attributed to necrotic enteritis (NE), whereas chicks fed both MOS or acidifier showed signs of NE related lesions. All dietary treatments were effective in reducing the numbers of C. perfringens in the ileum post challenge. The FED chicks had heavier body weight and numerically lower mortality. The FED chicks also showed stronger immune responses to NE challenge, showing enhanced (p<0.05) proliferation of T-cells. Early feeding of the MOS supplemented diet increased (p<0.05) IL-6 production. The relative bursa weight of the FED chicks was heavier at d 21 (p<0.05). All the additives increased the relative spleen weight of the HELD chicks at d 14 (p<0.05). The FED chicks had increased villus height and reduced crypt depth, and hence an increased villus/crypt ratio, especially in the jejunum at d 14 (p<0.05). The same was true for the HELD chicks given dietary additives (p<0.05). It may be concluded that the chicks with early access to dietary additives showed enhanced immune response and gut development, under C. perfringens challenge. The findings of this study shed light on managerial and nutritional strategies that could be used to prevent NE in the broiler industry without the use of in-feed antibiotics. PMID:25049595

Local Wound Care for Primary Cleft Lip Repair: Treatment and Outcomes With use of Topical Hydrogen Peroxide.

PubMed

Strong, Amy L; Nauta, Allison C; Kuang, Anna A

2015-12-01

This study highlights and validates a peroxide-based wound healing strategy for treatment of surgically closed facial wounds in a pediatric population. The authors identified pediatric patients undergoing primary cleft lip repair as a specific population to evaluate the outcomes of such a protocol. Through analysis of defined outcome measures, a reliable and reproducible protocol for postoperative wound care following primary cleft lip repair with favorable results is described. This retrospective study analyzes wound healing outcomes in pediatric patients undergoing primary cleft lip repair from 2006 to 2011 at a tertiary academic center. The wound healing protocol was used in both primary unilateral and bilateral repairs. One hundred fortysix patients between the ages of 0 and 4 years underwent primary cleft lip repair and cleft rhinoplasty by a single, fellowship-trained craniofacial surgeon. Postoperatively, wounds were treated with half-strength hydrogen peroxide and bacitracin, as well as scar massage. Incisional dehiscence, hypertrophic scar formation, discoloration, infection, and reoperation were studied. Outcomes were evaluated in light of parent compliance, demographics, preoperative nasoalveolar molding (PNAM), and diagnosis. The authors identified 146 patients for inclusion in this study. There was no wound or incisional dehiscence. One hundred twenty-four patients demonstrated favorable cosmetic outcome. Only 3 (2%) of patients who developed suboptimal outcomes underwent secondary surgical revision (> 1 year after surgery). Demographic differences were not statistically significant, and PNAM treatment did not influence outcomes. These data validate the use of halfstrength hydrogen peroxide and bacitracin as part of a wound healing strategy in pediatric incisional wounds. The use of hydrogen peroxide produced comparable outcomes to previously published studies utilizing other wound healing strategies and, therefore, these study findings support the

Myxospore Coat Synthesis in Myxococcus xanthus: In Vivo Incorporation of Acetate and Glycine

PubMed Central

Filer, D.; White, D.; Kindler, S. H.; Rosenberg, E.

1977-01-01

Myxospore coat synthesis in Myxococcus xanthus was studied by incorporation of [14C]acetate into intermediates in the biosynthesis of coat polysaccharide and into acid-insoluble material during vegetative growth and after glycerol induction of myxospores. During short labeling periods at 27°C, the radioactivity was shown to be located primarily in N-acetyl groups rather than sugar moieties. Two hours after glycerol induction, the pools of N-acetylglucosamine 6-phosphate and uridine 5′-diphosphate-N-acetylgalactosamine (UDPGalNAc) plus uridine 5′-diphosphate-N-glucosamine increased about twofold and were labeled at twice the rate measured for vegetative cells. The increased rate of synthesis of UDPGalNAc and its precursors could be correlated with increased enzyme activities measured in vitro. Controlled acid hydrolysis revealed that the galactosamine portion of the myxospore coat was N-acetylated. After glycerol induction, the incorporation of acetate into acid-insoluble material increased threefold. This enhanced incorporation was sensitive to neither penicillin nor d-cycloserine. In contrast, bacitracin inhibited the incorporation of [14C]acetate into acid-insoluble material more effectively 2 h after myxospore induction than during vegetative growth. Chloramphenicol added to cells 90 min after induction blocked further increase in the rate of [14C]acetate incorporation. Since the myxospore coat contains glycine, polymer synthesis was also measured by chloramphenicol-insensitive [14C]glycine incorporation into acid-insoluble material. Although protein synthesis decreased after glycerol induction, glycine incorporation increased. Two hours after induction, glycine incorporation was only 75% inhibited by chloramphenicol and rifampin. The chloramphenicol-insensitive rate of incorporation of [14C]glycine increased during the first hour after myxospore induction and reached a peak rate after 2 to 3 h. The chloramphenicol-resistant incorporation of [14C

Use of natural antimicrobials to increase antibiotic susceptibility of drug resistant bacteria.

PubMed

Palaniappan, Kavitha; Holley, Richard A

2010-06-15

Plant-derived antibacterial compounds may be of value as a novel means for controlling antibiotic resistant zoonotic pathogens which contaminate food animals and their products. Individual activity of natural antimicrobials (eugenol, thymol, carvacrol, cinnamaldehyde, allyl isothiocyanate (AIT)) and activity when paired with an antibiotic was studied using broth microdilution and checkerboard methods. In the latter assays, fractional inhibitory concentration (FIC) values were calculated to characterize interactions between the inhibitors. Bacteria tested were chosen because of their resistance to at least one antibiotic which had a known genetic basis. Substantial susceptibility of these bacteria toward the natural antimicrobials and a considerable reduction in the minimum inhibitory concentrations (MIC's) of the antibiotics were noted when paired combinations of antimicrobial and antibiotic were used. In the interaction study, thymol and carvacrol were found to be highly effective in reducing the resistance of Salmonella Typhimurium SGI 1 (tet A) to ampicillin, tetracycline, penicillin, bacitracin, erythromycin and novobiocin (FIC<0.4) and resistance of Streptococcus pyogenes ermB to erythromycin (FIC<0.5). With Escherichia coli N00 666, thymol and cinnamaldehyde were found to have a similar effect (FIC<0.4) in reducing the MIC's of ampicillin, tetracycline, penicillin, erythromycin and novobiocin. Carvacrol, thymol (FIC<0.3) and cinnamaldehyde (FIC<0.4) were effective against Staphylococcus aureus blaZ and in reducing the MIC's of ampicillin, penicillin and bacitracin. Allyl isothiocyanate (AIT) was effective in reducing the MIC of erythromycin (FIC<0.3) when tested against S. pyogenes. Fewer combinations were found to be synergistic when the decrease in viable population (log DP) was calculated. Together, fractional inhibitory concentrations < or = 0.5 and log DP<-1 indicated synergistic action between four natural antimicrobials and as many as three antibiotics

Selective medium for the isolation of Bacteroides gingivalis.

PubMed

Hunt, D E; Jones, J V; Dowell, V R

1986-03-01

Bacteroides gingivalis has been implicated in various forms of periodontal disease and may be responsible for other diseases in humans. The role of B. gingivalis in disease has been difficult to assess, because it is inhibited by most selective media commonly used by clinical laboratories to aid in isolating gram-negative, nonsporeforming anaerobes. We have developed a new medium, Bacteroides gingivalis agar, which contains bacitracin, colistin, and nalidixic acid as selective agents. This medium allowed B. gingivalis to be isolated from oral specimens with little difficulty and also allowed B. gingivalis to be isolated from phenotypically similar Bacteroides species, such as B. asaccharolyticus and B. endodontalis, with which it can easily be confused.

Dose—response relationships for agents inhibiting the immune response

PubMed Central

Berenbaum, M. C.; Brown, I. N.

1964-01-01

Mice were injected with T.A.B. vaccine and, 2 days later, with various doses of different compounds. The relation between dose of compound, mortality and antibody production was studied, and therapeutic indices were calculated for a number of compounds. The most effective agent in suppressing antibody production at relatively non-toxic doses was cyclophosphamide, with next amethopterin (the effect of which was, however, inexplicably erratic), 6-thioguanine and 6-mercaptopurine, in that order. Vincaleukoblastine, triethylene melamine, triethylenethiophosphoramide, mannomustine and 5-fluorouracil were less effective. Compounds of a miscellaneous group (boric acid, caffeine, sodium nitrite, bacitracin, neomycin and polymyxin `B') were studied in the same way: they had no effect on antibody production, even in lethal doses. PMID:14113077

Antimicrobial use surveillance in broiler chicken flocks in Canada, 2013-2015

PubMed Central

Irwin, Rebecca J.; Reid-Smith, Richard J.

2017-01-01

There is a paucity of data on the reason for and the quantity of antimicrobials used in broiler chickens in Canada. To address this, the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) implemented surveillance of antimicrobial use (AMU) and antimicrobial resistance (AMR) in broiler chicken flocks in 2013. Shortly after this (2014), the poultry industry banned the preventive use of ceftiofur in broiler chickens. The objectives of this analysis were to describe antimicrobial use (AMU) in Canadian broiler chickens between 2013 and 2015 (n = 378 flocks), compare these results to other animal species in Canada, to highlight the utility of farm surveillance data to evaluate the impact of a policy change, and to explore how different antimicrobial use metrics might affect data interpretation and communication. The surveillance data indicated that the poultry industry policy resulted in lower antimicrobial use and resistance, and they successfully captured information on when, where, why, and how much antimicrobials were being used. The majority of antimicrobials were administered via the feed (95%). The relative frequency of antimicrobial classes used in broiler chickens differed from those used in swine or in food animal production in general. Coccidiostats were the most frequently used antimicrobial classes (53% of total kg). Excluding coccidiostats, the top three most frequently used antimicrobial classes were bacitracin (53% of flocks), virginiamycin (25%) and avilamycin (21%), mainly used for the prevention of necrotic enteritis. Depending on the AMU metric utilized, the relative rankings of the top antimicrobials changed; hence the choice of the AMU metric is an important consideration for any AMU reporting. When using milligrams/Population Correction Unit (mg/PCU) the top three antimicrobial classes used were bacitracins (76 mg/PCU), trimethoprim-sulfonamides (24 mg/PCU), and penicillins (15 mg/PCU), whereas when using a number of

Presumptive identification and antibiotic susceptibility of group B streptococci.

PubMed Central

Jokipii, A M; Jokipii, L

1976-01-01

The comparative performance of three presumptive identification tests for group B haemolytic streptococci was investigated, using 371 different clinical isolates of group B streptococci. Hippurate was hydrolysed by 96-1%, the CAMP reaction was positive in 95-0%, and pigment was produced by 97-3%. A combination of any two tests would have detected over 99-8%. On bile esculin agar 99-0% were able to grow, but non hydrolysed esculin; 5-1% were susceptible to bacitracin. The minimum inhibitory concentrations of five antibiotics for 279 group B streptococci were determined. All were susceptible to penicillin G, ampicillin, cephalothin, and erythromycin, while 80% were resistant to tetracycline. The MIC distributions were independent of the results of any identification test. PMID:783206

Decolonization in Prevention of Health Care-Associated Infections.

PubMed

Septimus, Edward J; Schweizer, Marin L

2016-04-01

Colonization with health care-associated pathogens such as Staphylococcus aureus, enterococci, Gram-negative organisms, and Clostridium difficile is associated with increased risk of infection. Decolonization is an evidence-based intervention that can be used to prevent health care-associated infections (HAIs). This review evaluates agents used for nasal topical decolonization, topical (e.g., skin) decolonization, oral decolonization, and selective digestive or oropharyngeal decontamination. Although the majority of studies performed to date have focused on S. aureus decolonization, there is increasing interest in how to apply decolonization strategies to reduce infections due to Gram-negative organisms, especially those that are multidrug resistant. Nasal topical decolonization agents reviewed include mupirocin, bacitracin, retapamulin, povidone-iodine, alcohol-based nasal antiseptic, tea tree oil, photodynamic therapy, omiganan pentahydrochloride, and lysostaphin. Mupirocin is still the gold standard agent for S. aureus nasal decolonization, but there is concern about mupirocin resistance, and alternative agents are needed. Of the other nasal decolonization agents, large clinical trials are still needed to evaluate the effectiveness of retapamulin, povidone-iodine, alcohol-based nasal antiseptic, tea tree oil, omiganan pentahydrochloride, and lysostaphin. Given inferior outcomes and increased risk of allergic dermatitis, the use of bacitracin-containing compounds cannot be recommended as a decolonization strategy. Topical decolonization agents reviewed included chlorhexidine gluconate (CHG), hexachlorophane, povidone-iodine, triclosan, and sodium hypochlorite. Of these, CHG is the skin decolonization agent that has the strongest evidence base, and sodium hypochlorite can also be recommended. CHG is associated with prevention of infections due to Gram-positive and Gram-negative organisms as well as Candida. Conversely, triclosan use is discouraged, and topical

Antibiotic content of selective culture media for isolation of Capnocytophaga species from oral polymicrobial samples.

PubMed

Ehrmann, E; Jolivet-Gougeon, A; Bonnaure-Mallet, M; Fosse, T

2013-10-01

In oral microbiome, because of the abundance of commensal competitive flora, selective media with antibiotics are necessary for the recovery of fastidious Capnocytophaga species. The performances of six culture media (blood agar, chocolate blood agar, VCAT medium, CAPE medium, bacitracin chocolate blood agar and VK medium) were compared with literature data concerning five other media (FAA, LB, TSBV, CapR and TBBP media). To understand variable growth on selective media, the MICs of each antimicrobial agent contained in this different media (colistin, kanamycin, trimethoprim, trimethoprim-sulfamethoxazole, vancomycin, aztreonam and bacitracin) were determined for all Capnocytophaga species. Overall, VCAT medium (Columbia, 10% cooked horse blood, polyvitaminic supplement, 3·75 mg l(-1) of colistin, 1·5 mg l(-1) of trimethoprim, 1 mg l(-1) of vancomycin and 0·5 mg l(-1) of amphotericin B, Oxoid, France) was the more efficient selective medium, with regard to the detection of Capnocytophaga species from oral samples (P < 0·001) and the elimination of commensal clinical species (P < 0·001). The demonstrated superiority of VCAT medium, related to its antibiotic content, made its use indispensable for the optimal isolation of Capnocytophaga species from polymicrobial samples. Isolation of Capnocytophaga species is important for the proper diagnosis and treatment of the systemic infections they cause and for epidemiological studies of periodontal flora. We showed that in pure culture, a simple blood agar allowed the growth of all Capnocytophaga species. Nonetheless, in oral samples, because of the abundance of commensal competitive flora, selective media with antibiotics are necessary for the recovery of Capnocytophaga species. The demonstrated superiority of VCAT medium made its use essential for the optimal detection of this bacterial genus. This work showed that extreme caution should be exercised when reporting the isolation of Capnocytophaga

Decolonization in Prevention of Health Care-Associated Infections

PubMed Central

Schweizer, Marin L.

2016-01-01

SUMMARY Colonization with health care-associated pathogens such as Staphylococcus aureus, enterococci, Gram-negative organisms, and Clostridium difficile is associated with increased risk of infection. Decolonization is an evidence-based intervention that can be used to prevent health care-associated infections (HAIs). This review evaluates agents used for nasal topical decolonization, topical (e.g., skin) decolonization, oral decolonization, and selective digestive or oropharyngeal decontamination. Although the majority of studies performed to date have focused on S. aureus decolonization, there is increasing interest in how to apply decolonization strategies to reduce infections due to Gram-negative organisms, especially those that are multidrug resistant. Nasal topical decolonization agents reviewed include mupirocin, bacitracin, retapamulin, povidone-iodine, alcohol-based nasal antiseptic, tea tree oil, photodynamic therapy, omiganan pentahydrochloride, and lysostaphin. Mupirocin is still the gold standard agent for S. aureus nasal decolonization, but there is concern about mupirocin resistance, and alternative agents are needed. Of the other nasal decolonization agents, large clinical trials are still needed to evaluate the effectiveness of retapamulin, povidone-iodine, alcohol-based nasal antiseptic, tea tree oil, omiganan pentahydrochloride, and lysostaphin. Given inferior outcomes and increased risk of allergic dermatitis, the use of bacitracin-containing compounds cannot be recommended as a decolonization strategy. Topical decolonization agents reviewed included chlorhexidine gluconate (CHG), hexachlorophane, povidone-iodine, triclosan, and sodium hypochlorite. Of these, CHG is the skin decolonization agent that has the strongest evidence base, and sodium hypochlorite can also be recommended. CHG is associated with prevention of infections due to Gram-positive and Gram-negative organisms as well as Candida. Conversely, triclosan use is discouraged, and

The role of protein disulfide isomerase in the post-ligation phase of β3 integrin-dependent cell adhesion.

PubMed

Leader, Avi; Mor-Cohen, Ronit; Ram, Ron; Sheptovitsky, Vera; Seligsohn, Uri; Rosenberg, Nurit; Lahav, Judith

2015-12-01

Protein disulfide isomerase (PDI) catalyzes disulfide bond exchange. It is crucial for integrin-mediated platelet adhesion and aggregation and disulfide bond exchange is necessary for αIIbβ3 and αvβ3 activation. However, the role of disulfide bond exchange and PDI in the post-ligation phase of αIIbβ3 and αvβ3 mediated cell adhesion has yet to be determined. To investigate a possible such role, we expressed wild type (WT) human αIIb and either WT human β3, or β3 harboring single or double cysteine to serine substitutions disrupting Cys473-Cys503 or Cys523-Cys544 bonds, in baby hamster kidney (BHK) cells, leading to expression of both human αIIbβ3 and a chimeric hamster/human αvβ3. Adhesion to fibrinogen-coated wells was studied in the presence or absence of bacitracin, a PDI inhibitor, with and without an αvβ3 blocker. Flow cytometry showed WT and mutant αIIbβ3 expression in BHK cells and indicated that mutated αIIbβ3 receptors were constitutively active while WT αIIbβ3 was inactive. Both αIIbβ3 and αvβ3 integrins, WT and mutants, mediated adhesion to fibrinogen as shown by reduced but still substantial adhesion following treatment with the αvβ3 blocker. Mutated αIIbβ3 integrins disrupted in the Cys523-Cys544 bond still depended on PDI for adhesion as shown by the inhibitory effect of bacitracin in the presence of the αvβ3 blocker. Mutated integrins disrupted in the Cys473-Cys503 bond showed a similar trend. PDI-mediated disulfide bond exchange plays a pivotal role in the post-ligation phase of αIIbβ3-mediated adhesion to fibrinogen, while this step in αvβ3-mediated adhesion is independent of disulfide exchange. Copyright © 2015 Elsevier Ltd. All rights reserved.

Presumptive identification of streptococci with a new test system.

PubMed Central

Facklam, R R; Thacker, L G; Fox, B; Eriquez, L

1982-01-01

A test is described that could replace bacitracin susceptibility for presumptive identification of group A streptococci as well as 6.5% NaCl agar tolerance for presumptive identification of enterococcal streptococci. The L-pyrrolidonyl-beta-naphthylamide test, based on hydrolysis of pyrrolidonyl-beta-naphthylamide, was used in conjunction with the CAMP and bile-esculin tests to presumptively identify the streptococci. Among the beta-hemolytic streptococci; 98% of 50 group A, 98% of 46 group B, and 100% of 70 strains that were not group A, B, or D were correctly identified by the new presumptive test scheme. Among the non-beta-hemolytic streptococci; 96% of 74 group D enterococcal, 100% of 30 group D nonenterococcal, and 82% of 112 viridans strains were correctly identified by the new presumptive test scheme. PMID:7050157

Effect of disinfectants on stability and transmissibility of R-plasmid in E. coli isolated from drinking water.

PubMed

Tewari, Suman; Ramteke, Pramod W; Garg, S K

2003-03-01

Drug resistant enteropathogenic E. coli (EPEC, 086 serotype) isolated from contaminated piped drinking water supply (Fecal coliform 160/100 ml) was studied for effect of disinfectants (chlorine and UVB) on stability and transmissibility of R-plasmid. The strain was resistant to streptomycin and bacitracin and tolerant to multiple metal ions of Cd, Cr, Co, As, Ni, Zn and Hg. A plasmid of molecular size of 3.7 Kb was detected in the organism. After exposure to sublethal doses of disinfectants, complete elimination of resistances to streptomycin and Cr was observed. Partial loss of resistance to Hg due to chlorine was detected. Although UVB did not effected the pattern of transmissibility effect on frequency of transfer was observed. Surprisingly, in UVB irradiated cells, significantly enhanced rate of transfer was noted.

DELAYED APPEARANCE OF LACTOBACILLI IN THE INTESTINES OF CHICKS REARED IN A "NEW" ENVIRONMENT.

PubMed

BARE, L N; WISEMAN, R F

1964-11-01

Male chicks (1 day old; Vantress x Arbor Acre) were fed a basal folic acid-deficient diet, a 5% uric acid-containing diet with and without 5 mg/lb (453.5 g) of bacitracin and 20 mg/lb of sodium penicillin G, the basal diet supplemented with only the antibiotics, and the basal diet plus 500 mug/lb of folic acid. The chicks were reared in a room which had not been used previously for housing chickens ("new" environment). Bacteriological analyses of the contents of the small intestine revealed a decrease in numbers of streptococci and "anaerobic" bacteria in the chicks receiving dietary antibiotics. No persistent changes were seen in the numbers of coliform bacteria. Lactobacilli were not detected in any of the groups until 3 weeks after feeding.

[Controlled study of oral administration of antibiotics in the preparation of digestive surgery (author's transl)].

PubMed

Mendes da Costa, P; Klastersky, J; Gérard, A

1977-01-01

Between November 30, 1971 and March 15, 1976, 46 patients underwent surgery on the colon or rectum. They were randomized into 2 groups, one receiving a mechanical preparation together with lincomycline, neomycine, polymyxine, kanamycine, bacitracine and nystatine, the other a mechanical preparation alone. Analysis of results reveals no statistically significant difference in the frequency of infections, neither local (11/24 with antibiotics vis 13/22 without; chi2 = 0.25) neither general (16/24 and 9/22; chi2 = 0.92). Nor was the postoperative use of antibiotics for local or general infection different in the 2 groups. No influence of age or preoperative radio-therapy could be shown. This randomized trial suggests that there is little advantage in associating antibiotics to mechanical preparation before colorectal surgery. The authors contemplate a new randomized trial in high-risk patients suffering from cancer.

Antibacterial effect of electrolyzed water on oral bacteria.

PubMed

Lee, Sung-Hoon; Choi, Bong-Kyu

2006-08-01

This study investigated the antibacterial effect of electrolyzed water on oral bacteria both in vitro and in vivo. Tap water was electrolyzed in a water vessel using platinum cell technology. The electrolyzed tap water (called Puri-water) was put in contact with five major periodontopathogens or toothbrushes contaminated with these bacteria for 30 sec. In addition, Puri-water was used as a mouthwash for 30 sec in 16 subjects and the antibacterial effect on salivary bacteria was evaluated. Puri-water significantly reduced the growth of all periodontopathogens in culture and on toothbrushes, and that of aerobic and anaerobic bacteria in saliva, when compared to the effect of tap water. It also significantly reduced mutans streptococci growing on mitis salivarius-bacitracin agar. Our results demonstrate that the electrolyzed tap water is effective as a mouthwash and for toothbrush disinfection.

Incidence and Antimicrobial Susceptibility to Clostridium perfringens in Premarket Broilers in Taiwan.

PubMed

Fan, Yang-Chi; Wang, Chia-Lan; Wang, Chinling; Chen, Tsung-Cheng; Chou, Chung-Hsi; Tsai, Hsiang-Jung

2016-06-01

Clostridium perfringens infection causes subclinical and clinical necrotic enteritis in poultry flocks, and it is estimated to result in US$2 billion of losses worldwide every year. The aims of this study were to determine the incidence, toxin types, and antimicrobial resistance levels to C. perfringens isolated from premarket, 5-wk-old, clinically healthy broiler chickens in Taiwan, and to examine the relationships between intestinal lesions and the numbers of C. perfringens in intestinal contents. In total, 435 samples of chicken ileum contents were collected from 98 broiler farms during June 2012 to February 2013. The C. perfringens isolation rate was 9.9% (43/435). The positive rate of tested farms was 29.6% (29/98). All the isolates were C. perfringens type A, only possessing the cpa gene encoding for toxin α. No netB gene encoding NetB toxin associated with necrotic enteritis, and no cpe gene encoding for the C. perfringens enterotoxin causing human intestinal disorder were detected. A quantitative PCR analysis revealed that the mean C. perfringens number in the intestinal contents was 3.9 × 10(6) colony-forming units (CFU)/g, ranging from 6.85 × 10(2) to 1.61 × 10(7) CFU/g. The gross and histopathologic lesions revealed a positive correlation (p < 0.05) between lesion score and C. perfringens number in the ilea of C. perfringens -positive chickens. Antimicrobial susceptibility tests of all C. perfringens isolates indicated that the minimum inhibitory concentration inhibiting 50% of isolates (MIC50) for amoxicillin, bacitracin, chlortetracycline, enrofloxacin, erythromycin, florfenicol, and lincomycin was ≤0.125, 0.5, 128, 0.25, ≥256, 2, and ≥256 μg/ml, respectively. Most of the C. perfringens isolates were susceptible to amoxicillin, bacitracin, and enrofloxacin but resistant to chlortetracycline, erythromycin, and lincomycin. Interestingly, C. perfringens isolated from chickens with severe lesions had higher MIC50 for erythromycin and lincomycin

Transcriptome analysis of the responses of Staphylococcus aureus to antimicrobial peptides and characterization of the roles of vraDE and vraSR in antimicrobial resistance

PubMed Central

Pietiäinen, Milla; François, Patrice; Hyyryläinen, Hanne-Leena; Tangomo, Manuela; Sass, Vera; Sahl, Hans-Georg; Schrenzel, Jacques; Kontinen, Vesa P

2009-01-01

Background Understanding how pathogens respond to antimicrobial peptides, and how this compares to currently available antibiotics, is crucial for optimizing antimicrobial therapy. Staphylococcus aureus has several known resistance mechanisms against human cationic antimicrobial peptides (CAMPs). Gene expression changes in S. aureus strain Newman exposed to linear CAMPs were analyzed by DNA microarray. Three antimicrobial peptides were used in the analysis, two are derived from frog, temporin L and dermaseptin K4-S4(1-16), and the ovispirin-1 is obtained from sheep. Results The peptides induced the VraSR cell-wall regulon and several other genes that are also up-regulated in cells treated with vancomycin and other cell wall-active antibiotics. In addition to this similarity, three genes/operons were particularly strongly induced by the peptides: vraDE, SA0205 and SAS016, encoding an ABC transporter, a putative membrane-bound lysostaphin-like peptidase and a small functionally unknown protein, respectively. Ovispirin-1 and dermaseptin K4-S4(1-16), which disrupt lipid bilayers by the carpet mechanism, appeared to be strong inducers of the vraDE operon. We show that high level induction by ovispirin-1 is dependent on the amide modification of the peptide C-terminus. This suggests that the amide group has a crucial role in the activation of the Aps (GraRS) sensory system, the regulator of vraDE. In contrast, temporin L, which disrupts lipid bilayers by forming pores, revealed a weaker inducer of vraDE despite the C-terminal amide modification. Sensitivity testing with CAMPs and other antimicrobials suggested that VraDE is a transporter dedicated to resist bacitracin. We also showed that SA0205 belongs to the VraSR regulon. Furthermore, VraSR was shown to be important for resistance against a wide range of cell wall-active antibiotics and other antimicrobial agents including the amide-modified ovispirin-1, bacitracin, teicoplanin, cefotaxime and 10 other �

The Stress-Responsive dgk Gene from Streptococcus mutans Encodes a Putative Undecaprenol Kinase Activity

PubMed Central

Lis, Maciej; Kuramitsu, Howard K.

2003-01-01

We analyzed a previously constructed stress-sensitive Streptococcus mutans mutant Tn-1 strain resulting from disruption by transposon Tn916 of a gene encoding a protein exhibiting amino acid sequence similarity to the Escherichia coli diacylglycerol kinase. It was confirmed that the mutation led to significantly reduced lipid kinase activity, while expression of the intact gene on a plasmid restored both kinase activity and the wild-type phenotype. Further analysis revealed that the product of the dgk gene in S. mutans predominantly recognizes a lipid substrate other than diacylglycerol, most likely undecaprenol, as demonstrated by its efficient phosphorylation and the resistance of the product of the reaction to saponification. The physiological role of the product of the dgk gene as a putative undecaprenol kinase was further supported by a significantly higher sensitivity of the mutant to bacitracin compared with that of the parental strain. PMID:12654811

In vitro susceptibility of rabbit strains of Clostridium spiroforme to antimicrobial agents.

PubMed

Carman, R J; Wilkins, T D

1991-08-30

Using an agar dilution method we measured the minimum inhibitory concentration (MIC) of 12 antimicrobial agents against 11 strains of iota-toxigenic strains of Clostridium spiroforme. Each strain was isolated from a separate outbreak of toxic diarrhoea of rabbits. Vancomycin and bacitracin, both agents used to treat intestinal clostridioses of humans and other animals, had a relatively high MIC (8 micrograms/ml or more). Metronidazole was uniformly active against C. spiroforme. With MIC of 8 micrograms/ml or more, both lincomycin (11 strains) and erythromycin (9 strains) were relatively inactive against C. spiroforme, conversely, penicillin G was active (MIC for 8 strains was 0.5 micrograms/ml or less). Exposure to any one of these drugs has been implicated as a predisposing factor for C. spiroforme mediated diarrhoea of rabbits. The greatest variation in MIC was seen for erythromycin (8-fold), penicillin G (8-fold) and tetracycline (16-fold).

A hospital-based study to evaluate the incidence pattern of group A streptococcal throat infections from different age group patients.

PubMed

Ray, Dipanwita; Banerjee, Surajita; Bhattacharya, Sujata; Sinha, Sukanta; Bandyopadhyay, Debasis; Ghosal, Chaitry; Gupta, Siddhartha; Majumdar, Pallav Kumar; Saha, Somnath; Gupta, Soma; Bhattacharya, Basudev

2010-02-01

Streptococcus pyogenes(group A) is a major pathogen capable of causing a wide range of diseases in different age group of people. In this study 100 patients were selected who presented with the complaint of sore throat. All the patients were divided in four age groups. Streptococcus pyogenes colonies were confirmed on the basis of beta-haemolysis, bacitracin sensitivity test, and latex agglutination test for group A. Out of a total of 100 samples, 42 were confirmed as group A streptococcus. From this study, it has been observed that all age groups, with maximum occurrence in 5-15 years age group, were suffering from group A streptococcal pharyngitis. Therefore every case of sore throat especially affecting children should be investigated to detect the causative agent for initiation of proper therapy so that the more serious outcome like acute rheumatic fever (ARF) and acute glomerulonephritis (AGN) can be prevented.

Diagnosis of group A streptococcal infections directly from throat secretions.

PubMed Central

Edwards, E A; Phillips, I A; Suiter, W C

1982-01-01

The diagnosis of group A streptococcal disease still relies on isolation of group A streptococcal strains on sheep blood agar followed by presumptive identification based on bacitracin sensitivity or the results of the more precise serogrouping methods such as the Lancefield precipitin test. A technique that would permit rapid identification of streptococcal infections directly from throat secretions would allow immediate appropriate antimicrobial therapy for the management of streptococcal infections to be started. We have been able to identify soluble group A antigen directly from throat secretions by using a latex agglutination test. In a clinical trial in which latex (Streptex group A) and conventional culturing techniques were used, 53 throat secretion cultures were tested: 26 were positive by both procedures, 5 were positive by culture only, 3 were positive by the latex agglutination test only, and 19 were negative by both tests. Images PMID:7042747

Formate auxotroph of Methanobacterium thermoautotrophicum Marburg.

PubMed Central

Tanner, R S; McInerney, M J; Nagle, D P

1989-01-01

A formate-requiring auxotroph of Methanobacterium thermoautotrophicum Marburg was isolated after hydroxylamine mutagenesis and bacitracin selection. The requirement for formate is unique and specific; combined pools of other volatile fatty acids, amino acids, vitamins, and nitrogen bases did not substitute for formate. Compared with those of the wild type, cell extracts of the formate auxotroph were deficient in formate dehydrogenase activity, but cells of all of the strains examined catalyzed a formate-carbon dioxide exchange activity. All of the strains examined took up a small amount (200 to 260 mumol/liter) of formate (3 mM) added to medium. The results of the study of this novel auxotroph indicate a role for formate in biosynthetic reactions in this methanogen. Moreover, because methanogenesis from H2-CO2 is not impaired in the mutant, free formate is not an intermediate in the reduction of CO2 to CH4. PMID:2687241

Interventions for children with ear discharge occurring at least two weeks following grommet (ventilation tube) insertion.

PubMed

Venekamp, Roderick P; Javed, Faisal; van Dongen, Thijs Ma; Waddell, Angus; Schilder, Anne Gm

2016-11-17

quality of the evidence for each outcome; this is indicated in italics. We included nine studies, evaluating a range of treatments, with 2132 children who developed acute ear discharge beyond the immediate postoperative period. We judged the risk of bias to be low to moderate in most studies. Antibiotic eardrops (with or without corticosteroid) versus oral antibioticsAntibiotic eardrops with or without corticosteroid were more effective than oral antibiotics in terms of:- resolution of discharge at one week (one study, 42 children, ciprofloxacin eardrops versus amoxicillin: 77% versus 30%; risk ratio (RR) 2.58, 95% confidence interval (CI) 1.27 to 5.22; moderate-quality evidence);- resolution of discharge at two weeks (one study, 153 children, bacitracin-colistin-hydrocortisone eardrops versus amoxicillin-clavulanate: 95% versus 56%; RR 1.70, 95% CI 1.38 to 2.08; moderate-quality evidence);- duration of discharge (two studies, 233 children, ciprofloxacin eardrops versus amoxicillin: median 4 days versus 7 days and bacitracin-colistin-hydrocortisone eardrops versus amoxicillin-clavulanate: 4 days versus 5 days; moderate-quality evidence);- ear discharge recurrences (one study, 148 children, bacitracin-colistin-hydrocortisone eardrops versus amoxicillin-clavulanate: 0 versus 1 episode at six months; low-quality evidence); and- disease-specific quality of life (one study, 153 children, bacitracin-colistin-hydrocortisone eardrops versus amoxicillin-clavulanate: difference in change in median Otitis Media-6 total score (range 6 to 42) at two weeks: -2; low-quality evidence).We found no evidence that antibiotic eardrops were more effective in terms of the proportion of children developing chronic ear discharge or tube blockage, generic quality of life or hearing.Adverse events occurred at similar rates in children treated with antibiotic eardrops and those treated with oral antibiotics, while no serious complications occurred in either of the groups. Other comparisons

In vitro activities of ramoplanin, teicoplanin, vancomycin, linezolid, bacitracin, and four other antimicrobials against intestinal anaerobic bacteria.

PubMed

Citron, D M; Merriam, C V; Tyrrell, K L; Warren, Y A; Fernandez, H; Goldstein, E J C

2003-07-01

By using an agar dilution method, the in vitro activities of ramoplanin, teicoplanin, vancomycin, linezolid, and five other agents were determined against 300 gram-positive and 54 gram-negative strains of intestinal anaerobes. Ramoplanin was active at or=256 microg/ml. Ramoplanin displays excellent activity against C. difficile and other gram-positive enteric anaerobes, including vancomycin-resistant strains; however, it has poor activity against most gram-negative anaerobes and thus potentially has a lesser effect on the ecological balance of normal fecal flora.

In Vitro Activities of Ramoplanin, Teicoplanin, Vancomycin, Linezolid, Bacitracin, and Four Other Antimicrobials against Intestinal Anaerobic Bacteria

PubMed Central

Citron, D. M.; Merriam, C. V.; Tyrrell, K. L.; Warren, Y. A.; Fernandez, H.; Goldstein, E. J. C.

2003-01-01

By using an agar dilution method, the in vitro activities of ramoplanin, teicoplanin, vancomycin, linezolid, and five other agents were determined against 300 gram-positive and 54 gram-negative strains of intestinal anaerobes. Ramoplanin was active at ≤2 μg/ml against 287 of 300 (95.7%) gram-positive organisms, including 18 strains of Clostridium difficile for which MICs of ramoplanin were 0.25 to 0.5 μg/ml; for 3 of these, linezolid MICs were 8 to 16 μg/ml. Nineteen Clostridium innocuum strains for which the vancomycin MIC at which 90% of strains were inhibited was 16 μg/ml were susceptible to ramoplanin at 0.06 to 0.25 μg/ml and to teicoplanin at 0.125 to 1.0 μg/ml. All strains of Eubacterium, Actinomyces, Propionibacterium, and Peptostreptococcus spp. were inhibited by ≤0.25 μg of ramoplanin per ml and ≤1 μg of vancomycin per ml. Ramoplanin was also active at ≤4 μg/ml against 15 of 22 of the Prevotella and Porphyromonas strains tested, but ramoplanin MICs for all 31 strains of the Bacteroides fragilis group, the Fusobacterium mortiferum-Fusobacterium varium group, and Veillonella spp. were ≥256 μg/ml. Ramoplanin displays excellent activity against C. difficile and other gram-positive enteric anaerobes, including vancomycin-resistant strains; however, it has poor activity against most gram-negative anaerobes and thus potentially has a lesser effect on the ecological balance of normal fecal flora. PMID:12821492

Post-staining electroblotting for efficient and reliable peptide blotting.

PubMed

Lee, Der-Yen; Chang, Geen-Dong

2015-01-01

Post-staining electroblotting has been previously described to transfer Coomassie blue-stained proteins from polyacrylamide gel onto polyvinylidene difluoride (PVDF) membranes. Actually, stained peptides can also be efficiently and reliably transferred. Because of selective staining procedures for peptides and increased retention of stained peptides on the membrane, even peptides with molecular masses less than 2 kDa such as bacitracin and granuliberin R are transferred with satisfactory results. For comparison, post-staining electroblotting is about 16-fold more sensitive than the conventional electroblotting for visualization of insulin on the membrane. Therefore, the peptide blots become practicable and more accessible to further applications, e.g., blot overlay detection or immunoblotting analysis. In addition, the efficiency of peptide transfer is favorable for N-terminal sequence analysis. With this method, peptide blotting can be normalized for further analysis such as blot overlay assay, immunoblotting, and N-terminal sequencing for identification of peptide in crude or partially purified samples.

Antibiotic Therapy of Staphylococcal Infections

PubMed Central

Hawks, Gordon H.

1965-01-01

The antibiotic treatment of staphylococcal infections remains a problem. Isolation of the organism and sensitivity testing are necessary in the choice of antibiotic. Penicillin G is the most effective penicillin against non-penicillinase-producing staphy-lococci; for the penicillinase producers there is very little to choose between the semisynthetic penicillins, methicillin, cloxacillin, nafcillin and oxacillin. For patients who are hypersensitive to penicillin, the bacteriostatic drugs (erythromycin, novobiocin, tetracycline, chloramphenicol, oleandomycin) are useful for mild infections, while for more severe illness the bactericidal drugs (vancomycin, ristocetin, kanamycin, bacitracin, neomycin) have been used successfully. Acute staphylococcal enterocolitis is probably best treated by a semisynthetic penicillin. Other antibiotics which have been found useful, with clinical trials, for staphylococcal infections are cephalosporin, fucidin, cephaloridine and lincomycin. The latter drug has been reported of value in the treatment of osteomyelitis. There is little justification for the prophylactic use of antibiotics to prevent staphylococcal infection. Surgical drainage is still an important adjunct in the treatment of many staphylococcal infections. PMID:5318575

Evidence on Possible Mycoplasma Etiology of Aster Yellows Disease I. Suppression of Symptom Development in Plants by Antibiotics

PubMed Central

Davis, R. E.; Whitcomb, R. F.

1970-01-01

Antibiotics suppressed development of aster yellows (AY) disease symptoms in plants of china aster [Callistephus chinensis (L.) Nees.] and annual chrysanthemum (Chrysanthemum carinatum, Schousb.). When inoculated chrysanthemum plants were treated by any of several techniques with tetracycline antibiotics or chloramphenicol, symptoms failed to appear during treatment but appeared 1 to 4 weeks after treatments were terminated. Under continuous administration of chlortetracycline, aster plants with AY symptoms developed symptomless axillary growth, including flowers. Streptomycin, oleandomycin, kanamycin, tylosin, carbomycin, polymyxin, bacitracin, neomycin, sulfanilamide, penicillin, vancomycin, or cycloserine had no discernible effect on development of AY symptoms. Treatment of plants with tetracycline antibiotics before exposure to inoculative (pathogen-transmitting) vectors delayed the appearance of symptoms or prevented AY infection. Remission of AY symptoms in inoculated plants treated with chlortetracycline was correlated with an inhibition of multiplication of AY agent, as measured by bioassay of extracts. The data give additional support to the hypothesis that aster yellows disease is caused by a mycoplasma-like microorganism. Images PMID:16557820

FAD oxidizes the ERO1-PDI electron transfer chain: The role of membrane integrity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Papp, Eszter; Nardai, Gabor; Mandl, Jozsef

2005-12-16

The molecular steps of the electron transfer in the endoplasmic reticulum from the secreted proteins during their oxidation are relatively unknown. We present here that flavine adenine dinucleotide (FAD) is a powerful oxidizer of the oxidoreductase system, Ero1 and PDI, besides the proteins of rat liver microsomes and HepG2 hepatoma cells. Inhibition of FAD transport hindered the action of FAD. Microsomal membrane integrity was mandatory for all FAD-related oxidation steps downstream of Ero1. The PDI inhibitor bacitracin could inhibit FAD-mediated oxidation of microsomal proteins and PDI, but did not hinder the FAD-driven oxidation of Ero1. Our data demonstrated that Ero1more » can utilize FAD as an electron acceptor and that FAD-driven protein oxidation goes through the Ero1-PDI pathway and requires the integrity of the endoplasmic reticulum membrane. Our findings prompt further studies to elucidate the membrane-dependent steps of PDI oxidation and the role of FAD in redox folding.« less

EFFECT OF DIETARY ANTIBIOTICS UPON COLIFORM BACTERIA AND LACTOBACILLI IN THE INTESTINAL TRACT OF URIC ACID-FED CHICKS.

PubMed

BARE, L N; WISEMAN, R F; ABBOTT, O J

1964-02-01

Bare, L. N. (University of Kentucky, Lexington), R. F. Wiseman, and O. J. Abbott. Effect of dietary antibiotics upon coliform bacteria and lactobacilli in the intestinal tract of uric acid-fed chicks. J. Bacteriol. 87:329-331. 1964.-Male chicks (1-day-old; Vantress X Arbor Acre) were fed a basal glucose-soybean oil meal diet, a 2% uric acid-containing diet with and without 5 mg/lb of zinc bacitracin and 20 mg/lb of procaine penicillin G, and one supplemented with the antibiotics only. After 4 weeks, the chicks receiving the uric acid without antibiotics showed a weight depression. The presence of antibiotics in the ration with the uric acid reversed this growth depression. Bacteriological and chemical analyses of the contents of the small intestine revealed an increase in numbers of uricolytic Aerobacter spp. and an increased degradation of uric acid in the tract of the "uric-antibiotic"-fed chicks. The counts of lactobacilli were always lowest in this group of chicks

The effect of broad-spectrum antibiotics on warfarin excretion and metabolism in the rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Remmel, R.P.; Elmer, G.W.

The excretion and metabolism of /sup 14/C-warfarin in rats was examined in a crossover experiment, the first phase consisting of treatment with normal saline, the second phase using the same animals given neomycin, bacitracin, and tetracycline orally. Urine and feces were collected every 24 hours for 72 hours and examined for warfarin and its metabolites, both unconjugated and conjugated. Significantly more radioactivity was eliminated in th feces of antibiotic-treated rats. The feces of antibiotic-treated rats contained only trace amounts of beta-glucuronidase activity. Urine contained a similar ratio of unconjugated to conjugated radioactivity in both treatment groups, but the antibiotic-treated animalsmore » had significantly larger amount of conjugates in their feces. Examination of metabolic profiles of conjugated and unconjugated fractions revealed significantly fewer hydroxylated metabolites in antibiotic-treated rats, especially in the feces. The lower amount of hydroxylative metabolism in attributed to a reduction in gut flora-medicated interohepatic recycling caused by the antibiotics.« less

Antibiotic growth promoter-induced changes in the chicken intestine: A metabolomics analysis of virginiamycin and bacitracin methylene disalicylate

USDA-ARS?s Scientific Manuscript database

Abstract Although dietary antibiotic growth promoters have long been used to increase growth performance in commercial food animal production, the biochemical details associated with these effects remain poorly defined. A metabolomics approach was used to characterize and identify the biochemical co...

Small-molecule elicitation of microbial secondary metabolites.

PubMed

Pettit, Robin K

2011-07-01

Microbial natural products continue to be an unparalleled resource for pharmaceutical lead discovery, but the rediscovery rate is high. Bacterial and fungal sequencing studies indicate that the biosynthetic potential of many strains is much greater than that observed by fermentation. Prodding the expression of such silent (cryptic) pathways will allow us to maximize the chemical diversity available from microorganisms. Cryptic metabolic pathways can be accessed in the laboratory using molecular or cultivation-based approaches. A targeted approach related to cultivation-based methods is the application of small-molecule elicitors to specifically affect transcription of secondary metabolite gene clusters. With the isolation of the novel secondary metabolites lunalides A and B, oxylipins, cladochromes F and G, nygerone A, chaetoglobosin-542, -540 and -510, sphaerolone, dihydrosphaerolone, mutolide and pestalone, and the enhanced production of known secondary metabolites like penicillin and bacitracin, chemical elicitation is proving to be an effective way to augment natural product libraries. © 2010 The Authors. Journal compilation © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

Comparative recovery of Streptococcus mutans on ten isolation media.

PubMed

Little, W A; Korts, D C; Thomson, L A; Bowen, W H

1977-06-01

The ability of Streptococcus mutans (Bratthall serotypes a through e) to grow on 10 isolation media was examined. The number and morphology of the colonies were observed to vary on different media. The use of blood-sucrose media consistently produced the highest recoveries. Mitis salivarius agar (MS) and higher recovery values than modified medium 10 (MM10SB), Trypticase-yeast extract-cystine medium (TYC), or MS with 1% tellurite (MST). MST with 40% sucrose (MS40S), MST with 20% sucrose and 0.2 U of bacitracin per ml (MSB), and Carlsson medium with 1% sulfasoxazole (MC), media formulated for the selection of S. mutans, were the most inhibitory for all serotypes. The morphology of several S. mutans strains was atypical on MC and MS40S, making positive identification difficult. Absence of growth of serotype a strains on MSB and serotype d strains on MC were the two major differences observed among the serotypes. Results are discussed in terms of the difficulties in making quantitative determinations from cultural data.

Multidrug resistance in Clostridium perfringens isolated from diarrheal neonatal piglets in Thailand.

PubMed

Ngamwongsatit, Bhinyada; Tanomsridachchai, Wimonrat; Suthienkul, Orasa; Urairong, Supanee; Navasakuljinda, Wichian; Janvilisri, Tavan

2016-04-01

Clostridium perfringens causes diarrhea in neonatal piglets, thereby affecting commercial swine farming. The objective of this study was to determine the prevalence and characterize antimicrobial resistance in C. perfringens isolated from diarrheal neonatal piglets in Thailand. A total of 260 rectal swab samples were collected from 13 farms and were subjected to C. perfringens isolation. A total of 148 samples were PCR-positive for C. perfringens toxin genes, from which 122 were recovered. All isolates were cpb2-encoding C. perfringens type A and enterotoxin gene negative. Most of the isolates were susceptible to ampicillin, bacitracin, chlorotetracycline, doxycycline, and oxytetracycline with MIC50 values ranging from 0.32 to 8 μg/ml. The high resistance rates were observed for ceftiofur, enrofloxacin, erythromycin, lincomycin, and tylosin. Among resistant isolates, 82% were resistant to more than one type of antibiotics. The distinct pattern of multiple drug resistance in C. perfringens was observed in different regions, potentially reflecting the farm specific usage of these agents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Protein disulfide isomerases: Impact of thapsigargin treatment on their expression in melanoma cell lines.

PubMed

Silva, Zélia; Veríssimo, Teresa; Videira, Paula A; Novo, Carlos

2015-08-01

Anti-cancer treatments usually elevate the content of unfolded or misfolded proteins in the endoplasmic reticulum (ER). Here we aimed to get insights into the relation between sensitivity of melanoma cell lines to the ER stress inducer thapsigargin (THG) and the genetic expression of protein disulfide isomerase family members (PDIs). The expression of PDIs was analysed by flow cytometry and real-time PCR. The results showed that SK-MEL-30, the less THG sensitive cell line, displays higher basal PDIs' expression levels and the sensitivity is increased by the PDIs inhibitor bacitracin. While SK-MEL-30 PDIs' expression is not THG dose-dependent, an increase in glucose related protein 78 (GRP78), PDIA5, PDIA6, and thioredoxin-related-transmembrane proteins' (TMX3 and TMX4) expression, in response to higher drug concentrations, was observed in MNT-1. The differences in PDIs' gene expression in MNT-1 suggest a different response to ER stress compared to the other cell lines and highlight the importance of understanding the diversity among cancer cells. Copyright © 2015 Elsevier B.V. All rights reserved.

The blue man: burn from muriatic acid combined with chlorinated paint in an adult pool construction worker.

PubMed

O'Cleireachain, Marc R; Macias, Luis H; Richey, Karen J; Pressman, Melissa A; Shirah, Gina R; Caruso, Daniel M; Foster, Kevin N; Matthews, Marc R

2014-01-01

Muriatic acid (hydrochloric acid), a common cleaning and resurfacing agent for concrete pools, can cause significant burn injuries. When coating a pool with chlorinated rubber-based paint, the pool surface is initially cleansed using 31.45% muriatic acid. Here we report a 50-year-old Hispanic male pool worker who, during the process of a pool resurfacing, experienced significant contact exposure to a combination of muriatic acid and blue chlorinated rubber-based paint. Confounding the clinical situation was the inability to efficiently remove the chemical secondary to the rubber-based nature of the paint. Additionally, vigorous attempts were made to remove the rubber paint using a variety of agents, including bacitracin, chlorhexidine soap, GOOP adhesive, and Johnson's baby oil. Resultant injuries were devastating fourth-degree burns requiring an immediate operative excision and amputation. Despite aggressive operative intervention and resuscitation, he continued to have severe metabolic derangements and ultimately succumbed to his injuries. We present our attempts at debridement and the system in place to manage patients with complex chemical burns.

Combating Drug Resistant Pathogenic Bacteria Isolated from Clinical Infections, with Silver Oxide Nanoparticles

PubMed Central

Sangappa, M.; Thiagarajan, Padma

2015-01-01

The antibiogram study of methicillin resistant Staphylococcus aureus isolates revealed 100% resistance to vancomycin, bacitracin, erythromycin, ciprofloxacin and nalidixic acid. Eight isolates (53.3%) showed resistance to co-trimoxazole and one isolate to rifampicin, which was the drug of choice. An effort was made to evaluate the antimethicillin resistant Staphylococcus aureus activity of silver oxide (Ag2O) nanoparticles synthesized from Aspergillus terreus VIT 2013. Production of Ag2O nanoparticles was confirmed by color change of fungal filtrate and UV light absorption at 450 nm. X-ray diffraction pattern showed 2θ values at 27, 32, 38 and 57°, which corresponded to the cubic structure of Ag2O nanocrystals. Fourier transform infrared spectroscopy indicated the presence of primary amine, carbonyl group, NO2 and silver, revealing protein mediated nanoparticle production. The scanning electron microscope image showed freely dispersed Ag2O nanoparticles. The nanoparticles were active against all methicillin resistant isolates and hence can be used as antibacterial agents against drug resistant bacteria. PMID:26009646

Growth of Streptococcus mutans on various selective media.

PubMed

Emilson, C G; Bratthall, D

1976-07-01

The ability of Streptococcus mutans to grow on mitis-salivarius (MS) agar, MC agar, mitis-sucrose-bacitracin (MSB), BCY agar, and MM10 sucrose agar was studied. Batch cultures of S. mutans serotype a demonstrated no growth on MSB agar. Certain serotype d and g strains did not grow on MC agar. The yield for most strains of other serotypes on these selective media was lower compared with that on MS agar. The number of total colony-forming units on BCY and MM10 sucrose agar was similar to the blood agar results. Similar data were obtained when fermenter-grown strains, harvested in the middle or the end of the logarithmic growth phase, were used for inoculation of the various media. Enumeration of S. mutans from plaque samples plated on MC and MSB agar yielded about 75% of the counts obtained on MS or the nonselective medium. When the proportions of S. mutans were expressed as a percentage of the total cultivable flora, the selective media (MC and MSB agar) showed approximately 10% lower values than the MS, BCY, and MM10 sucrose agar.

Allergic contact dermatitis from medical adhesive bandages in patients who report having a reaction to medical bandages.

PubMed

Widman, Travis J; Oostman, Holly; Storrs, Frances J

2008-01-01

Medical adhesive bandages are extensively used in both inpatient and outpatient medicine. However, few reports describing proven allergic contact dermatitis (ACD) from medical adhesive bandages exist in the literature. These reports do not adequately correspond to the frequency that patients report having an "allergy" to medical adhesive bandages. To determine if there is a chemical present in medical adhesive bandages that causes ACD in people who identify themselves as having an "allergy" to medical adhesive bandages. Twenty-six patients were enrolled and underwent patch testing with our standard trays (104 chemicals) and a customized adhesive tray (54 chemicals and 10 tapes and bandages in their whole form). We were able to identify an allergen in four patients that was related to their presumed adhesive allergy (Mastisol, neomycin/bacitracin [two different patients], and cortisone-10 cream, respectively). However, there were no positive allergic reactions to the tapes or bandages or any relevant allergic reactions to our customized adhesive tray. Eight (73%) of the 11 patients who had the bandage or tape left on for 7 days had an irritant reaction. We feel that the perceived reactions are not secondary to ACD but instead are due to an irritant contact dermatitis.

Salivary secretory IgA, pH, flow rates, mutans streptococci and Candida in children with rampant caries.

PubMed

Thaweboon, Sroisiri; Thaweboon, Boonyanit; Nakornchai, Siriruk; Jitmaitree, Sukritta

2008-09-01

The aim of this study was to determine the levels of secretory IgA (SIgA), pH, flow rates, mutans streptococci (MS) and Candida in saliva of children with rampant caries compared to those caries-free. Thirty children (age 62-123 months) were enrolled and divided into two groups: Group I, children with rampant caries, Group II, caries-free children. The average salivary flow rate was measured from the volume yielded within 5 minutes and the pH was determined using a pH-electrode. Measurement of SIgA was performed using an immunoassay kit. The levels of MS and Candida were determined by culture on Mitis-Salivarius Bacitracin agar and Sabouraud dextrose agar. It was found that children with rampant caries presented with significantly higher levels of salivary SIgA, MS and Candida. However, the mean values for salivary flow rates and pH were similar between the groups. The results reveal that children with rampant caries had significantly higher levels of SIgA, MS and Candida in their oral cavities. This finding tends to support the hypothesis that higher levels of salivary SIgA may reflect a past exposure of the host to cariogenic microorganisms.

Clinical use of photodynamic antimicrobial chemotherapy for the treatment of deep carious lesions

NASA Astrophysics Data System (ADS)

Guglielmi, Camila De Almeida B.; Simionato, Maria Regina L.; Ramalho, Karen Müller; Imparato, José Carlos P.; Pinheiro, Sérgio Luiz; Luz, Maria A. A. C.

2011-08-01

The purpose of this study was to assess photodynamic antimicrobial chemotherapy (PACT) via irradiation, using a low power laser associated with a photosensitization dye, as an alternative to remove cariogenic microorganisms by drilling. Remaining dentinal samples in deep carious lesions on permanent molars (n = 26) were treated with 0.01% methylene blue dye and irradiated with a low power laser (InGaAIP - indium gallium aluminum phosphide; λ = 660 nm; 100 mW; 320 Jcm-2 90 s; 9J). Samples of dentin from the pulpal wall region were collected with a micropunch before and immediately after PACT and kept in a transport medium for microbiological analysis. Samples were cultured in plates of Brucella blood agar, Mitis Salivarius Bacitracin agar and Rogosa SL agar to determine the total viable bacteria, mutans streptococci and Lactobacillus spp. counts, respectively. After incubation, colony-forming units were counted and microbial reduction was calculated for each group of bacteria. PACT led to statistically significant reductions in mutans streptococci (1.38 log), Lactobacillus spp. (0.93 log), and total viable bacteria (0.91 log). This therapy may be an appropriate approach for the treatment of deep carious lesions using minimally invasive procedures.

Metagenomic insights into ultraviolet disinfection effects on antibiotic resistome in biologically treated wastewater.

PubMed

Hu, Qing; Zhang, Xu-Xiang; Jia, Shuyu; Huang, Kailong; Tang, Junying; Shi, Peng; Ye, Lin; Ren, Hongqiang

2016-09-15

High-throughput sequencing-based metagenomic approaches were used to comprehensively investigate ultraviolet effects on the microbial community structure, and diversity and abundance of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) in biologically treated wastewater. After ultraviolet radiation, some dominant genera, like Aeromonas and Halomonas, in the wastewater almost disappeared, while the relative abundance of some minor genera including Pseudomonas and Bacillus increased dozens of times. Metagenomic analysis showed that 159 ARGs within 14 types were detectable in the samples, and the radiation at 500 mJ/cm(2) obviously increased their total relative abundance from 31.68 ppm to 190.78 ppm, which was supported by quantitative real time PCR. As the dominant persistent ARGs, multidrug resistance genes carried by Pseudomonas and bacitracin resistance gene bacA carried by Bacillus mainly contributed to the ARGs abundance increase. Bacterial community shift and MGEs replication induced by the radiation might drive the resistome alteration. The findings may shed new light on the mechanism behind the ultraviolet radiation effects on antibiotic resistance in wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

Use of Lactobacillus johnsonii in broilers challenged with Salmonella sofia.

PubMed

Olnood, Chen G; Beski, Sleman S M; Choct, Mingan; Iji, Paul A

2015-09-01

The effects of Lactobacillus johnsonii (L. johnsonii) on gut microflora, bird performance and intestinal development were assessed using 288 one-day-old Cobb broilers challenged with Salmonella sofia ( S . sofia ). The experiment was a 3 × 2 factorial design which consisted of three treatments, a negative control (NC) with no additives, a positive control (PC) containing antimicrobials (zinc-bacitracin, 50 mg/kg) and a probiotic group (Pro), and with the two factors being unchallenged or challenged with S . sofia . A probiotic preparation of L . johnsonii (10 9 cfu/chick) was administered to chicks individually by oral gavage on days 1, 3, 7 and 12. Chicks were individually challenged with S. sofia (10 7 cfu/chick) by oral gavage on d 2, 8 and 13. Results showed that the challenge itself markedly reduced ( P < 0.05) bird performance and feed intake. And, transient clinical symptoms of the infection with S . sofia were observed from the second time they were challenged with S . sofia in the negative challenge groups. The novel probiotic candidate L . johnsonii reduced the number of S . sofia and Clostridium perfringens in the gut environment, and improved the birds' colonization resistance to S . sofia .

Antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products.

PubMed

Katla, A K; Kruse, H; Johnsen, G; Herikstad, H

2001-07-20

Commercial starter culture bacteria are widely used in the production of dairy products and could represent a potential source for spread of genes encoding resistance to antimicrobial agents. To learn more about the antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products, a total of 189 isolates of lactic acid bacteria were examined for susceptibility to ampicillin, penicillin G, cephalothin, vancomycin, bacitracin, gentamicin, streptomycin, erythromycin, tetracycline, chloramphenicol, quinupristin/dalfopristin, ciprofloxacin, trimethoprim and sulphadiazine using Etest for MIC determination. Most of the isolates (140) originated from 39 dairy products (yoghurt, sour cream, fermented milk and cheese), while 49 were isolated directly from nine commercial cultures. The bacteria belonged to the genera Lactobacillus, Lactococcus, Leuconostoc and Streptococcus. Only one of the 189 isolates was classified as resistant to an antimicrobial agent included in the study. This isolate, a lactobacillus, was classified as high level resistant to streptomycin. The remaining isolates were not classified as resistant to the antimicrobial agents included other than to those they are known to have a natural reduced susceptibility to. Thus, starter culture bacteria in Norwegian dairy products do not seem to represent a source for spread of genes encoding resistance to antimicrobial agents.

Randomized noninferiority field trial evaluating cephapirin sodium for treatment of nonsevere clinical mastitis.

PubMed

Tomazi, T; Lopes, T A F; Masson, V; Swinkels, J M; Santos, M V

2018-05-16

The general objective of this study was to evaluate whether cephapirin sodium is noninferior compared with a positive control broad-spectrum product formulated with a combination of antimicrobials for intramammary treatment of nonsevere clinical mastitis. In addition, we compared the efficacy of treatments on the cure risks of pathogen groups (gram-positive, gram-negative, and cultures with no growth) based on culture results. A total of 346 cows distributed in 31 commercial dairy herds were selected to participate in the study, although only 236 met the criteria for evaluation of microbiological cure. Coagulase-negative staphylococci were the most isolated gram-positive pathogens in pretreatment milk samples, whereas the most common gram-negative bacterium was Escherichia coli. Cows attending the postadmission criteria were treated with 4 intramammary infusions (12 h apart) of one of the following antimicrobials: 300 mg of cephapirin sodium + 20 mg of prednisolone (CS), or the positive control treatment formulated with a combination of antimicrobials (200 mg of tetracycline + 250 mg of neomycin + 28 mg of bacitracin + 10 mg of prednisolone; TNB). Noninferiority analysis and mixed regression models (overall and considering the pathogen groups) were performed for the following outcomes: bacteriological cure (absence of the causative pathogens in cultures performed in milk samples collected at 14 and 21 ± 3 d after enrollment), pathogen cure (absence of any pathogen on both follow-up samples), clinical cure (absence of clinical sign in the milk and mammary gland at 48 h after the last antimicrobial infusion), extended clinical cure (normal milk and normal gland on the second posttreatment sample collection (d 21), and linear score of somatic cell count cure [linear score of somatic cell count recovery (≤4.0) on d 21 ± 3 after enrollment]. No significant differences were observed between treatments regarding any of the evaluated outcomes in both regression models

Occupational dermatitis in health care workers evaluated for suspected allergic contact dermatitis.

PubMed

Kadivar, Salmon; Belsito, Donald V

2015-01-01

Contact dermatitides occur commonly among health care workers (HCWs). To contrast the atopic status and incidence, location, and final diagnosis of skin diseases afflicting HCWs versus non-HCWs (NHCWs) evaluated for suspicion of allergic contact dermatitis (ACD); and among the population diagnosed with ACD, to compare the incidence and occupational relatedness of allergens found in HCWs with the rates observed in NHCWs. Between July 1, 1994, and May 30, 2014, 2611 patients underwent patch testing by the senior author. Of these, 165 were classified as HCWs based on their primary occupation. Statistical analysis was done using a χ test. Health care workers were more likely than NHCWs to be women and to have hand dermatitis. Women, but not men, HCWs suffered more irritant contact dermatitis. Health care workers had significantly more work-related ACD, especially to formaldehyde, quaternium-15, 2-bromo-2-nitropropane-1,3-diol, cocamide diethanolamine (DEA), thiuram mix, carba mix, thimerosal, benzalkonium chloride, glutaraldehyde, and bacitracin. Only patients suspected of having ACD were tested. Our population was geographically limited to metropolitan Kansas City, MO and metropolitan New York, NY. Health care workers suffer more from occupational ACD, especially of the hands, than do NHCWs, including to allergens not present on available standard allergen series.

Bacterial Community Shift Drives Antibiotic Resistance Promotion during Drinking Water Chlorination.

PubMed

Jia, Shuyu; Shi, Peng; Hu, Qing; Li, Bing; Zhang, Tong; Zhang, Xu-Xiang

2015-10-20

For comprehensive insights into the effects of chlorination, a widely used disinfection technology, on bacterial community and antibiotic resistome in drinking water, this study applied high-throughput sequencing and metagenomic approaches to investigate the changing patterns of antibiotic resistance genes (ARGs) and bacterial community in a drinking water treatment and distribution system. At genus level, chlorination could effectively remove Methylophilus, Methylotenera, Limnobacter, and Polynucleobacter, while increase the relative abundance of Pseudomonas, Acidovorax, Sphingomonas, Pleomonas, and Undibacterium in the drinking water. A total of 151 ARGs within 15 types were detectable in the drinking water, and chlorination evidently increased their total relative abundance while reduced their diversity in the opportunistic bacteria (p < 0.05). Residual chlorine was identified as the key contributing factor driving the bacterial community shift and resistome alteration. As the dominant persistent ARGs in the treatment and distribution system, multidrug resistance genes (mainly encoding resistance-nodulation-cell division transportation system) and bacitracin resistance gene bacA were mainly carried by chlorine-resistant bacteria Pseudomonas and Acidovorax, which mainly contributed to the ARGs abundance increase. The strong correlation between bacterial community shift and antibiotic resistome alteration observed in this study may shed new light on the mechanism behind the chlorination effects on antibiotic resistance.

Antimicrobial resistance of Listeria spp. recovered from processed bison.

PubMed

Li, Q; Sherwood, J S; Logue, C M

2007-01-01

The current study examined the antimicrobial susceptibility of 86 Listeria spp. isolated from processed bison carcasses. Susceptibility to 25 antimicrobial agents was determined using E-test and National Antimicrobial Resistance Monitoring System (NARMS) panels. Most Listeria isolates (88-98%) exhibited resistance to bacitracin, oxacillin, cefotaxime, and fosfomycin. Resistance to tetracycline (18.6%) was also common. Of the 16 tetracycline-resistant Listeria isolates, 15 carried tetM and 2 contained integrase of Tn1545 transposons. Rifampicin and trimethoprim-sulfamethoxazole were the most active antimicrobial agents against Listeria spp., with a MIC(90) of 0.38 microg ml(-1). Ampicillin, erythromycin, penicillin, gentamicin, and tobramycin also exhibited good activity against Listeria spp., with MIC(90) not exceeding 1 microg ml(-1). Differences in resistance among Listeria spp. was displayed, as Listeria innocua strains were more resistant than other Listeria species. The study showed that Listeria monocytogenes strains from bison were susceptible to the antibiotics most commonly used to treat human listeriosis. However, the presence of antimicrobial resistance in L. innocua indicates the potential for transfer of resistance and a conjugative transposon to L. monocytogenes. The findings of our study will provide useful information for the development of public health policy in the use of antimicrobials in food animal production.

Prevalence of β-hemolytic Streptococcus in children with special health care needs.

PubMed

Morais, Viviane Martha Santos de; Orsi, Alice Ramos; Maranhão, Fernanda Cristina de Albuquerque; Castro, Therezita Maria Peixoto Patury Galvão; Castro, Karina Cavalcante Beltrão de; Silva, Denise Maria Wanderlei

2012-10-01

Pharyngotonsillitis by β-hemolytic Streptococcus mostly affects children and immunocompromised, being Streptococcus pyogenes (Group A) the most common agent in bacterial pharyngotonsillitis. This work targeted the research of β-hemolytic Streptococcus Group-A (SBHGA) and No-A (SBHGNA) in the oropharynx of individuals with special health needs from the APAE (Maceió-AL). A prospective study with oropharynx samples from patients with Down syndrome and other mental disorders (test) and students from a private school (control) aged 5-15 years. Cultures in blood agar (5%) were identified through Gram/catalase tests and bacitracin/trimethoprim-sulfamethoxazole disk diffusion method, applying the chi-squared statistical analysis. A total of 222 bacterial colonies were isolated in 74 individuals from APAE and 65 in the control group. In the test group, previous episodes of pharyngotonsillitis were reported by 36.49% (27/74) and 9.46% (7/74) were diagnosed with symptoms and/or signs suggestive of oropharynx infection. No positive sample of S. pyogenes was confirmed at APAE, being all samples classified as SBHGNA, with 5 SBHGA in the control group. The early identification of β-hemolytic Streptococcus is important for the fast treatment of pharyngotonsillitis and the absence of S. pyogenes avoid future suppurative or not-suppurative sequels in the group from APAE.

Identification and antimicrobial suceptibility profile of bacteria causing bovine mastitis from dairy farms in Pelotas, Rio Grande do Sul.

PubMed

Freitas, C H; Mendes, J F; Villarreal, P V; Santos, P R; Gonçalves, C L; Gonzales, H L; Nascente, P S

2018-01-08

Mastitis is an inflammatory process of the udder tissue caused mainly by the bacteria Staphylococcus aureus. The indiscriminate use of antibiotics fosters conditions that favor the selection of resistant microorganisms, suppressing at the same time susceptible forms, causing a serious problem in dairy cattle. Given the importance in performing an antibiogram to select the most adequate antimicrobial therapy, the aim of this study was to identify bacteria isolated from cow's milk with mastitis, in dairy farms situated in the city of Pelotas, Rio Grande do Sul, and to determinate the susceptibility profile of these isolates against the antibiotics used to treat this illness. A total of 30 isolates of Staphylococcus spp., were selected from milk samples from the udder quarters with subclinical mastitis whose species were identified through the Vitek system. The susceptibility profile was performed by the disk diffusion assay, against: ampicillin, amoxicillin, bacitracin, cephalexin, ceftiofur, enrofloxacin, gentamicin, neomycin, norfloxacin, penicillin G, tetracycline and trimethoprim. In the antibiogram, 100.0% of the isolates were resistant to trimethoprim and 96.7% to tetracycline and neomycin, three strains of Staphylococcus spp., (10.0%) presented resistance to the 12 antibiotics tested and 24 (80.0%) to at least eight. These results showed the difficulty in treating mastitis, due to the pathogens' resistance.

Comparative antibiogram of coagulase-negative Staphylococci (CNS) associated with subclinical and clinical mastitis in dairy cows.

PubMed

Bansal, B K; Gupta, D K; Shafi, T A; Sharma, S

2015-03-01

The present study was planned to determine the in vitro antibiotic susceptibility of coagulase-negative Staphylococci (CNS) strains isolated from clinical and subclinical cases of mastitis in dairy cows. Antibiotic sensitivity profile will be helpful to recommend early therapy at the field level prior to availability of CST results. The milk samples from cases of clinical mastitis received in Mastitis Laboratory, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana and those of subclinical mastitis collected during routine screening of state dairy farms, were subjected to microbial culture. Identification of CNS organisms was done by standard biochemical tests. Antibiotic sensitivity testing, based on 30 antibiotics belonging to 12 groups, was done on 58 randomly selected CNS isolates (clinical isolates: 41, subclinical isolates: 17). Isolates were highly susceptible to chloramphenicol (98.3%), gentamicin (93.1%), streptomycin (91.4%), linezolid (91.4%), ceftixozime (87.9%), cloxacillin (86.2%), clotrimazole (86.2%), bacitracin (86.2%), enrofloxacin (84.5%) and ceftrioxone + tazobactum (70.7%), while resistance was observed against amoxicillin (77.6%), penicillin (75.9%), ampicillin (74.1%) and cefoperazone (51.7%). Overall, isolates from clinical cases of mastitis had a higher resistance than subclinical isolates. CNS isolates were susceptible to chloramphenicol, gentamicin and streptomycin, while higher resistance was recorded against routinely used penicillin group.

Inhibitors of peptidases: how they influence the biological activities of substance P, neurokinins, bradykinin and angiotensin in guinea pig, hamster and rat urinary bladders.

PubMed

Rouissi, N; Nantel, F; Drapeau, G; Rhaleb, N E; Dion, S; Regoli, D

1990-01-01

Neurokinins, bradykinin and angiotensins were tested in isolated urinary bladder of the guinea pig, the hamster and the rat, in the absence and in presence of a variety of peptidase inhibitors in order to establish if peptide degradation interferes with the bladder contractions elicited by the three types of peptides. Indeed, the effects of neurokinins, bradykinin and angiotensin I in the guinea pig bladder were significantly enhanced by captopril (4.6 x 10(-6) mol/l), chymostatin (1 mg/l), phosphoramidon (4.6 x 10(-6) mol/l) and thiorphan (1.0 x 10(-6) mol/l), while only captopril was found to potentiate the effects of the same peptides in the rat bladder. The four peptidase inhibitors, as well as bacitracin were found to modify the responses of the hamster urinary bladder to one or another or to all three groups of peptides and to DiMeC7. The present results suggest that the urinary bladders of various species have different types of active proteolytic enzymes: only the angiotensin-converting enzyme appears to be present in the rat bladder, while the same enzyme and possibly two additional endopeptidases interfere with the myotropic effects of neurokinins, kinins and angiotensins in the guinea pig and the hamster bladder.

Deciphering the mode of action of cell wall-inhibiting antibiotics using metabolic labeling of growing peptidoglycan in Streptococcus pyogenes.

PubMed

Sugimoto, Atsushi; Maeda, Asuka; Itto, Kaori; Arimoto, Hirokazu

2017-04-25

Because of the scanty pipeline of antibiotics newly obtained from nature, chemical modification of established drugs is one of the major streams of current antibacterial research. Intuitive and easy-to-use assays are critical for identifying drug candidates with novel modes of action. In this study, we demonstrated that metabolic fluorescent staining of growing cell walls is a powerful tool for mode-of-action analyses of antibiotics using Streptococcus pyogenes. A set of major cell-wall-inhibiting antibiotics (bacitracin, D-cycloserine, flavomycin, oxacillin, ramoplanin, and vancomycin) was employed to validate the potential of the assay. The mechanistic differences of these antibiotics were successfully observed. For instance, D-cycloserine treatment induced fluorescently stained, excessive peripheral cell wall growth. This may indicate that the switch from the peripheral growth stage to the succeeding septal growth was disturbed by the treatment. We then applied this assay to analyze a series of vancomycin derivatives. The assay was sufficiently sensitive to detect the effects of single-site chemical modification of vancomycin on its modes of action. This metabolic fluorescent labeling method is easy to perform, especially because it does not require radiolabeled substrates. Thus, it is suitable for the preliminary evaluation of antibacterial mechanisms during antibacterial research.

Effects of Different Zinc Species on Cellar Zinc Distribution, Cell Cycle, Apoptosis and Viability in MDAMB231 Cells.

PubMed

Wang, Yan-hong; Zhao, Wen-jie; Zheng, Wei-juan; Mao, Li; Lian, Hong-zhen; Hu, Xin; Hua, Zi-chun

2016-03-01

Intracellular metal elements exist in mammalian cells with the concentration range from picomoles per litre to micromoles per litre and play a considerable role in various biological procedures. Element provided by different species can influence the availability and distribution of the element in a cell and could lead to different biological effects on the cell's growth and function. Zinc as an abundant and widely distributed essential trace element, is involved in numerous and relevant physiological functions. Zinc homeostasis in cells, which is regulated by metallothioneins, zinc transporter/SLC30A, Zrt-/Irt-like proteins/SLC39A and metal-response element-binding transcription factor-1 (MTF-1), is crucial for normal cellular functioning. In this study, we investigated the influences of different zinc species, zinc sulphate, zinc gluconate and bacitracin zinc, which represented inorganic, organic and biological zinc species, respectively, on cell cycle, viability and apoptosis in MDAMB231 cells. It was found that the responses of cell cycle, apoptosis and death to different zinc species in MDAMB231 cells are different. Western blot analysis of the expression of several key proteins in regulating zinc-related transcription, cell cycle, apoptosis, including MTF-1, cyclin B1, cyclin D1, caspase-8 and caspase-9 in treated cells further confirmed the observed results on cell level.

Crosstalk between Zinc Status and Giardia Infection: A New Approach

PubMed Central

Astiazarán-García, Humberto; Iñigo-Figueroa, Gemma; Quihui-Cota, Luis; Anduro-Corona, Iván

2015-01-01

Zinc supplementation has been shown to reduce the incidence and prevalence of diarrhea; however, its anti-diarrheal effect remains only partially understood. There is now growing evidence that zinc can have pathogen-specific protective effects. Giardiasis is a common yet neglected cause of acute-chronic diarrheal illness worldwide which causes disturbances in zinc metabolism of infected children, representing a risk factor for zinc deficiency. How zinc metabolism is compromised by Giardia is not well understood; zinc status could be altered by intestinal malabsorption, organ redistribution or host-pathogen competition. The potential metal-binding properties of Giardia suggest unusual ways that the parasite may interact with its host. Zinc supplementation was recently found to reduce the rate of diarrhea caused by Giardia in children and to upregulate humoral immune response in Giardia-infected mice; in vitro and in vivo, zinc-salts enhanced the activity of bacitracin in a zinc-dose-dependent way, and this was not due to zinc toxicity. These findings reflect biological effect of zinc that may impact significantly public health in endemic areas of infection. In this paper, we shall explore one direction of this complex interaction, discussing recent information regarding zinc status and its possible contribution to the outcome of the encounter between the host and Giardia. PMID:26046395

Expedient antibiotics production: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bienkowski, P.R.; Byers, C.H.; Lee, D.D.

The literature on the manufacture, separation and purification, and clinical uses of antibiotics was reviewed, and a bibliography of the pertinent material was completed. Five antimicrobial drugs, penicillin V and G, (and amoxicillin with clavulanic acid), Cephalexin (a cephalosporin), tetracycline and oxytetracycline, Bacitracin (topical), and sulfonamide (chemically produced) were identified for emergency production. Plants that manufacture antibiotics in the continental United States, Mexico, and Puerto Rico have been identified along with potential alternate sites such as those where SCP, enzyme, and fermentation ethanol are produced. Detailed process flow sheets and process descriptions have been derived from the literature and documented.more » This investigation revealed that a typical antibiotic-manufacturing facility is composed of two main sections: (1) a highly specialized, but generic, fermentation unit and (2) a multistep, complex separation and purification unit which is specific to a particular antibiotic product. The fermentation section requires specialized equipment for operation in a sterile environment which is not usually available in other industries. The emergency production of antibiotics under austere conditions will be feasible only if a substantial reduction in the complexity and degree of separation and purity normally required can be realized. Detailed instructions were developed to assist state and federal officials who would be directing the resumption of antibiotic production after a nuclear attack. 182 refs., 54 figs., 26 tabs.« less

Pediatric Contact Dermatitis Registry Inaugural Case Data.

PubMed

Goldenberg, Alina; Mousdicas, Nico; Silverberg, Nanette; Powell, Douglas; Pelletier, Janice L; Silverberg, Jonathan I; Zippin, Jonathan; Fonacier, Luz; Tosti, Antonella; Lawley, Leslie; Wu Chang, Mary; Scheman, Andrew; Kleiner, Gary; Williams, Judith; Watsky, Kalman; Dunnick, Cory A; Frederickson, Rachel; Matiz, Catalina; Chaney, Keri; Estes, Tracy S; Botto, Nina; Draper, Michelle; Kircik, Leon; Lugo-Somolinos, Aida; Machler, Brian; Jacob, Sharon E

2016-01-01

Little is known about the epidemiology of allergic contact dermatitis (ACD) in US children. More widespread diagnostic confirmation through epicutaneous patch testing is needed. The aim was to quantify patch test results from providers evaluating US children. The study is a retrospective analysis of deidentified patch test results of children aged 18 years or younger, entered by participating providers in the Pediatric Contact Dermatitis Registry, during the first year of data collection (2015-2016). One thousand one hundred forty-two cases from 34 US states, entered by 84 providers, were analyzed. Sixty-five percent of cases had one or more positive patch test (PPT), with 48% of cases having 1 or more relevant positive patch test (RPPT). The most common PPT allergens were nickel (22%), fragrance mix I (11%), cobalt (9.1%), balsam of Peru (8.4%), neomycin (7.2%), propylene glycol (6.8%), cocamidopropyl betaine (6.4%), bacitracin (6.2%), formaldehyde (5.7%), and gold (5.7%). This US database provides multidisciplinary information on pediatric ACD, rates of PPT, and relevant RPPT reactions, validating the high rates of pediatric ACD previously reported in the literature. The registry database is the largest comprehensive collection of US-only pediatric patch test cases on which future research can be built. Continued collaboration between patients, health care providers, manufacturers, and policy makers is needed to decrease the most common allergens in pediatric consumer products.

Prevalence and Antibiogram Assessment of Staphylococcus aureus in Beef at Municipal Abattoir and Butcher Shops in Addis Ababa, Ethiopia.

PubMed

Adugna, Feben; Pal, Mahendra; Girmay, Gebrerufael

2018-01-01

A cross-sectional study was conducted from October 2013 to April 2014 to determine the prevalence and antibiotic resistance of Staphylococcus aureus from beef of Addis Ababa Abattoir and butcher shops in Addis Ababa. Seven hundred sixty-eight swab samples were taken from the abattoir and butcher carcasses using a systematic random sampling. One hundred twenty swab samples were also taken from hooks, cutting tables, and knives from the abattoir. Staphylococcus aureus positive isolates were taken for antibiotic susceptibility test. A questionnaire survey was conducted in the abattoir and butcher workers to assess the hygienic practice and possible risk factors regarding the contamination of meat. The prevalence of S. aureus in the abattoir, butcher, cutting table, hook, and knife was 9.4%, 19.8%, 15%, 15%, and 22.5%, respectively. The prevalence of S. aureus in the knife and butcher was found to be 2.8 (OR = 2.8, CI = 1.2-6.4) and 2.4 (OR = 2.4, CI = 1.6-3.6) times that of the abattoir results ( p < 0.01). The antimicrobial susceptibility testing was also conducted on 133 isolates of S. aureus using the disc diffusion susceptibility method. Bacitracin, neomycin, and methicillin were found to be 100% resistant to S. aureus . To avoid the presence of pathogenic Staphylococcus isolates, preventive measures using good hygienic practices during slaughtering and handling of the beef carcasses are recommended.

A watertight acrylic-free titanium recording chamber for electrophysiology in behaving monkeys

PubMed Central

Economides, John R.; Jocson, Cristina M.; Parker, John M.; Horton, Jonathan C.

2011-01-01

Neurophysiological recording in alert monkeys requires the creation of a permanent aperture in the skull for repeated insertion of microelectrodes. Most laboratories use polymethyl methacrylate to attach a recording chamber over the skull opening. Here, we describe a titanium chamber that fastens to the skull with screws, using no polymethyl methacrylate. The gap between the base of the chamber and the skull is filled with hydroxyapatite, forming a watertight gasket. As the chamber base osseointegates with the skull, the hydroxyapatite is replaced with bone. Rather than having a finite lifetime, the recording chamber becomes more firmly anchored the longer it is in place. It has a small footprint, low profile, and needs little maintenance to control infection. Toilette consists of occasional application of betadine to clean the scalp margin, followed by application of neomycin, polymyxin, and bacitracin ointment. Antibiotic is also placed inside the chamber to suppress bacterial proliferation. Thickening of the dura within the chamber can be prevented by regular application of mitocycin C and/or bevacizumab, an antibody against vascular endothelial growth factor. By conducting an e-mail survey, this protocol for chamber maintenance was compared with procedures used in 37 other vision research laboratories. Refinement of appliances and techniques used for recordings in awake monkeys promises to increase the pace of scientific discovery and to benefit animal welfare. PMID:21676928

Isolation and Pathogenicity of Streptococcus iniae in Cultured Red Hybrid Tilapia in Malaysia.

PubMed

Rahmatullah, M; Ariff, M; Kahieshesfandiari, M; Daud, H M; Zamri-Saad, M; Sabri, M Y; Amal, M N A; Ina-Salwany, M Y

2017-12-01

This study describes the isolation and pathogenicity of Streptococcus iniae in cultured red hybrid tilapia (Nile Tilapia Oreochromis niloticus × Mozambique Tilapia O. mossambicus) in Malaysia. The isolated gram-positive S. iniae appeared punctiform, transparently white, catalase and oxidase negative and produced complete β-hemolysis on blood agar, while a PCR assay resulted in the amplification of the 16 S rRNA gene and lactate oxidase encoded genes. The isolate was sensitive to tetracycline, vancomycin, and bacitracin but was resistant to streptomycin, ampicillin, penicillin, and erythromycin. Pathogenicity trials conducted in local red hybrid tilapia (mean ± SE = 20.00 ± 0.45 g) showed 90.0, 96.7, and 100.0% mortality within 14 d postinfection following intraperitoneal exposure to 10 4 , 10 6 , and 10 8 CFU/mL of the pathogen, respectively. The clinical signs included erratic swimming, lethargy, and inappetance at 6 h postinfection, while mortality was recorded at less than 24 h postinfection in all infected groups. The LD 50-336 h of S. iniae against the red hybrid tilapia was 10 2 CFU/mL. The post mortem examinations revealed congested livers, kidneys, and spleens of the infected fish. This is the first report of S. iniae experimental infection in cultured red hybrid tilapia in Malaysia. Received January 20, 2017; accepted July 16, 2017.

Genome Analysis of F. nucleatum sub spp vincentii and Its Comparison With the Genome of F. nucleatum ATCC 25586

PubMed Central

Kapatral, Vinayak; Ivanova, Natalia; Anderson, Iain; Reznik, Gary; Bhattacharyya, Anamitra; Gardner, Warren L.; Mikhailova, Natalia; Lapidus, Alla; Larsen, Niels; D'Souza, Mark; Walunas, Theresa; Haselkorn, Robert; Overbeek, Ross; Kyrpides, Nikos

2003-01-01

We present the draft genome sequence and its analysis for Fusobacterium nucleatum sub spp. vincentii (FNV), and compare that genome with F. nucleatum ATCC 25586 (FN). A total of 441 FNV open reading frames (ORFs) with no orthologs in FN have been identified. Of these, 118 ORFs have no known function and are unique to FNV, whereas 323 ORFs have functional orthologs in other organisms. In addition to the excretion of butyrate, H2S and ammonia-like FN, FNV has the additional capability to excrete lactate and aminobutyrate. Unlike FN, FNV is likely to incorporate galactopyranose, galacturonate, and sialic acid into its O-antigen. It appears to transport ferrous iron by an anaerobic ferrous transporter. Genes for eukaryotic type serine/threonine kinase and phosphatase, transpeptidase E-transglycosylase Pbp1A are found in FNV but not in FN. Unique ABC transporters, cryptic phages, and three types of restriction-modification systems have been identified in FNV. ORFs for ethanolamine utilization, thermostable carboxypeptidase, γ glutamyl-transpeptidase, and deblocking aminopeptidases are absent from FNV. FNV, like FN, lacks the classical catalase-peroxidase system, but thioredoxin/glutaredoxin enzymes might alleviate oxidative stress. Genes for resistance to antibiotics such as acriflavin, bacitracin, bleomycin, daunorubicin, florfenicol, and other general multidrug resistance are present. These capabilities allow Fusobacteria to survive in a mixed culture in the mouth. PMID:12799352

Morphological Changes and Antibiotic-Induced Thermal Resistance in Vegetative Cells of Bacillus subtilis

PubMed Central

Dul, Michael J.; McDonald, William C.

1971-01-01

The morphology and thermal resistance of vegetative cells of Bacillus subtilis W168 were examined after growth at 37 and 53 C. Vegetative cells grown at 37 C exhibited a typical trilaminar morphology, whereas cells grown at 53 C exhibited a cell wall which was apparently thicker and more loosely organized and had a poorly defined periphery. A concurrent increase in thermal resistance to a heat shock of 60 C occurs with the change in cell wall morphology. The change to the aberrant cell wall form, or its reversal to the normal form, is always accompanied by the gain or the loss of thermal resistance, respectively. The inhibition of protein synthesis by chloramphenicol has little effect upon the acquisition of thermal resistance at 53 C. Addition of the disaccharide pentapeptide subunit to the cell wall peptidoglycan is apparently essential to growth at 53 C and the acquisition of thermal resistance, since both growth and thermal resistance are inhibited by bacitracin. Two antibiotics, penicillin and cycloserine, which inhibit the final cross-linking of the cell wall peptidoglycan at two separate points, do not affect the acquisition of thermal resistance at 53 C. These same antibiotics induce a high degree of thermal resistance at 37 C. It is proposed that a change in the cell wall structure is related to an increased thermal resistance. Images PMID:4995654

A global perspective on the use, sales, exposure pathways, occurrence, fate and effects of veterinary antibiotics (VAs) in the environment

USGS Publications Warehouse

Sarmah, Ajit K.; Meyer, Michael T.; Boxall, Alistair B.A.

2006-01-01

Veterinary antibiotics (VAs) are widely used in many countries worldwide to treat disease and protect the health of animals. They are also incorporated into animal feed to improve growth rate and feed efficiency. As antibiotics are poorly adsorbed in the gut of the animals, the majority is excreted unchanged in faeces and urine. Given that land application of animal waste as a supplement to fertilizer is often a common practice in many countries, there is a growing international concern about the potential impact of antibiotic residues on the environment. Frequent use of antibiotics has also raised concerns about increased antibiotic resistance of microorganisms. We have attempted in this paper to summarize the latest information available in the literature on the use, sales, exposure pathways, environmental occurrence, fate and effects of veterinary antibiotics in animal agriculture. The review has focused on four important groups of antibiotics (tylosin, tetracycline, sulfonamides and, to a lesser extent, bacitracin) giving a background on their chemical nature, fate processes, occurrence, and effects on plants, soil organisms and bacterial community. Recognising the importance and the growing debate, the issue of antibiotic resistance due to the frequent use of antibiotics in food-producing animals is also briefly covered. The final section highlights some unresolved questions and presents a way forward on issues requiring urgent attention.

Mechanism of action of a novel recombinant peptide, MP1102, against Clostridium perfringens type C.

PubMed

Zong, Lifen; Teng, Da; Wang, Xiumin; Mao, Ruoyu; Yang, Na; Hao, Ya; Wang, Jianhua

2016-06-01

This work is the first to report the antibacterial characteristics and antibacterial mechanisms of MP1102, which is a variant of NZ2114, against pathogenic Clostridium perfringens. MP1102 exhibited strong antimicrobial activity against C. perfringens strains CVCC 61, CVCC 1163, and CVCC 2032 at a low minimal inhibitory concentration (MIC) of 0.91 μM. MP1102 showed anti-C. perfringens activity over a wide pH range of 2.0 and 10.0, high thermal stability from 20 to 80 °C, and remarkable resistance to pepsin. The fractional inhibitory concentration index (FICI) indicated an additive or synergic effect between MP1102 and bacitracin zinc, nisin, vancomycin, virginiamycin, aureomycin, and ampicillin against C. perfringens (FICI = 0.3125-1.0). To further elucidate the antibacterial mechanism of MP1102, its effect on the C. perfringens CVCC 61 cell membrane and intracellular DNA was studied. Flow cytometry and scanning electron microscopy (SEM) indicated that MP1102 treatment resulted in the release of cellular contents by damaging the membrane. A DNA gel retardation and circular dichroism analysis demonstrated that MP1102 interacted with DNA and intercalated into the DNA base pairs. A cell cycle assay demonstrated that MP1102 affected cellular functions, such as DNA synthesis. These results suggested that MP1102 exhibited potential as a new antimicrobial agent against C. perfringens infections.

Cell envelope stress response in cell wall-deficient L-forms of Bacillus subtilis.

PubMed

Wolf, Diana; Domínguez-Cuevas, Patricia; Daniel, Richard A; Mascher, Thorsten

2012-11-01

L-forms are cell wall-deficient bacteria that can grow and proliferate in osmotically stabilizing media. Recently, a strain of the Gram-positive model bacterium Bacillus subtilis was constructed that allowed controlled switching between rod-shaped wild-type cells and corresponding L-forms. Both states can be stably maintained under suitable culture conditions. Because of the absence of a cell wall, L-forms are known to be insensitive to β-lactam antibiotics, but reports on the susceptibility of L-forms to other antibiotics that interfere with membrane-anchored steps of cell wall biosynthesis are sparse, conflicting, and strongly influenced by strain background and method of L-form generation. Here we investigated the response of B. subtilis to the presence of cell envelope antibiotics, with regard to both antibiotic resistance and the induction of the known LiaRS- and BceRS-dependent cell envelope stress biosensors. Our results show that B. subtilis L-forms are resistant to antibiotics that interfere with the bactoprenol cycle, such as bacitracin, vancomycin, and mersacidin, but are hypersensitive to nisin and daptomycin, which both affect membrane integrity. Moreover, we established a lacZ-based reporter gene assay for L-forms and provide evidence that LiaRS senses its inducers indirectly (damage sensing), while the Bce module detects its inducers directly (drug sensing).

Insulation and wiring specificity of BceR-like response regulators and their target promoters in Bacillus subtilis.

PubMed

Fang, Chong; Nagy-Staroń, Anna; Grafe, Martin; Heermann, Ralf; Jung, Kirsten; Gebhard, Susanne; Mascher, Thorsten

2017-04-01

BceRS and PsdRS are paralogous two-component systems in Bacillus subtilis controlling the response to antimicrobial peptides. In the presence of extracellular bacitracin and nisin, respectively, the two response regulators (RRs) bind their target promoters, P bceA or P psdA , resulting in a strong up-regulation of target gene expression and ultimately antibiotic resistance. Despite high sequence similarity between the RRs BceR and PsdR and their known binding sites, no cross-regulation has been observed between them. We therefore investigated the specificity determinants of P bceA and P psdA that ensure the insulation of these two paralogous pathways at the RR-promoter interface. In vivo and in vitro analyses demonstrate that the regulatory regions within these two promoters contain three important elements: in addition to the known (main) binding site, we identified a linker region and a secondary binding site that are crucial for functionality. Initial binding to the high-affinity, low-specificity main binding site is a prerequisite for the subsequent highly specific binding of a second RR dimer to the low-affinity secondary binding site. In addition to this hierarchical cooperative binding, discrimination requires a competition of the two RRs for their respective binding site mediated by only slight differences in binding affinities. © 2016 John Wiley & Sons Ltd.

Umbilical Negative Pressure Dressing for Transumbilical Appendectomy in Childern.

PubMed

Seifarth, Federico G; Kundu, Neilendu; Guerron, Alfredo D; Garland, Mary M; Gaffley, Michaela W G; Worley, Sarah; Knight, Colin G

2016-01-01

Transumbilical laparoscopic-assisted appendectomy (TULAA) carries a high risk for surgical site infection. We investigated the effect of a bio-occlusive umbilical vacuum dressing on wound infection rates after TULAA for patients with acute appendicitis and compared to it with a conventional 3-port appendectomy with a nonvacuum dressing. This study was a retrospective chart review of 1377 patients (2-20 years) undergoing laparoscopic appendectomy for acute appendicitis in 2 tertiary care referral centers from January 2007 through December 2012. Twenty-two different operative technique/dressing variations were documented. The 6 technique/dressing groups with >50 patients were assessed, including a total of 1283 patients. The surgical site infection rate of the 220 patients treated with TULAA and application of an umbilical vacuum dressing with dry gauze is 1.8% (95% CI, 0.0-10.3%). This compares to an infection rate of 4.1% (95% CI, 1.3-10.5%) in 97 patients with dry dressing without vacuum. In the 395 patients who received an umbilical vacuum dressing with gauze and bacitracin, the surgical site infection rate was found to be 4.3% (95% CI, 2.7-6.8%). Application of an umbilical negative-pressure dressing with dry gauze lowers the rate of umbilical site infections in patients undergoing transumbilical laparoscopic-assisted appendectomy for acute appendicitis.

Recolonization of mutans Streptococci after application of chlorhexidine gel.

PubMed

Vale, Glauber Campos; Cury, Altair Antoninha Del Bel; Arthur, Rodrigo Alex; Cury, Jaime Aparecido; Tabchoury, Cínthia Pereira Machado

2014-01-01

Streptococcus mutans is specifically suppressed by intensive treatment with chlorhexidine gel, but the time for recolonization and the effect on other oral bacteria are not totally clear. In this study, recolonization of mutans streptococci was evaluated in nine healthy adult volunteers, who were highly colonized with this microorganism. Stimulated saliva was collected before (baseline) and at 1, 7, 14, 21 and 28 days after application of 1% chlorhexidine gel on volunteers' teeth for two consecutive days. On each day, the gel was applied using disposable trays for 3 x 5 min with intervals of 5 min between each application. Saliva was plated on blood agar to determine total microorganisms (TM); on mitis salivarius agar to determine total streptococci (TS) and on mitis salivarius agar plus bacitracin to determine mutans streptococci (MS). Chlorhexidine was capable of reducing the counts of MS and the proportion of MS with regard to total microorganisms (%MS/TM) (p<0.05), but these values did not differ statistically from baseline (p>0.05) after 14 days for MS and 21 days for %MS/TM. The counts of TM and TS and the proportion of MS to total streptococci did not differ statistically from baseline (p>0.05) after chlorhexidine treatment. The results suggest that the effect of chlorhexidine gel treatment on suppression of mutans streptococci is limited to less than a month in highly colonized individuals.

Cell Envelope Stress Response in Cell Wall-Deficient L-Forms of Bacillus subtilis

PubMed Central

Wolf, Diana; Domínguez-Cuevas, Patricia; Daniel, Richard A.

2012-01-01

L-forms are cell wall-deficient bacteria that can grow and proliferate in osmotically stabilizing media. Recently, a strain of the Gram-positive model bacterium Bacillus subtilis was constructed that allowed controlled switching between rod-shaped wild-type cells and corresponding L-forms. Both states can be stably maintained under suitable culture conditions. Because of the absence of a cell wall, L-forms are known to be insensitive to β-lactam antibiotics, but reports on the susceptibility of L-forms to other antibiotics that interfere with membrane-anchored steps of cell wall biosynthesis are sparse, conflicting, and strongly influenced by strain background and method of L-form generation. Here we investigated the response of B. subtilis to the presence of cell envelope antibiotics, with regard to both antibiotic resistance and the induction of the known LiaRS- and BceRS-dependent cell envelope stress biosensors. Our results show that B. subtilis L-forms are resistant to antibiotics that interfere with the bactoprenol cycle, such as bacitracin, vancomycin, and mersacidin, but are hypersensitive to nisin and daptomycin, which both affect membrane integrity. Moreover, we established a lacZ-based reporter gene assay for L-forms and provide evidence that LiaRS senses its inducers indirectly (damage sensing), while the Bce module detects its inducers directly (drug sensing). PMID:22964256

Antimicrobial effects of herbal extracts on Streptococcus mutans and normal oral streptococci.

PubMed

Lee, Sung-Hoon

2013-08-01

Streptococcus mutans is associated with dental caries. A cariogenic biofilm, in particular, has been studied extensively for its role in the formation of dental caries. Herbal extracts such as Cudrania tricuspidata, Sophora flavescens, Ginkgo biloba, and Betula Schmidtii have been used as a folk remedy for treating diseases. The purpose of this study was to evaluate and compare the antibacterial activity of herbal extracts against normal oral streptococci, planktonic and biofilm of S. mutans. Streptococcus gordonii, Streptococcus oralis, Streptococcus salivarius, Streptococcus sanguinis, and S. mutans were cultivated with brain heart infusion broth and susceptibility assay for the herbal extracts was performed according to the protocol of Clinical and Laboratory Standard Institute. Also, S. mutans biofilm was formed on a polystyrene 12-well plate and 8-well chamber glass slip using BHI broth containing 2% sucrose and 1% mannose after conditioning the plate and the glass slip with unstimulated saliva. The biofilm was treated with the herbal extracts in various concentrations and inoculated on Mitis-Salivarius bacitracin agar plate for enumeration of viable S. mutans by counting colony forming units. Planktonic S. mutans showed susceptibility to all of the extracts and S. mutans biofilm exhibited the highest level of sensitivity for the extracts of S. flavescens. The normal oral streptococci exhibited a weak susceptibility in comparison to S. mutans. S. oralis, however, was resistant to all of the extracts. In conclusion, the extract of S. flavescens may be a potential candidate for prevention and management of dental caries.

Antibiotic Susceptibility Evaluation of Group A Streptococcus Isolated from Children with Pharyngitis: A Study from Iran.

PubMed

Sayyahfar, Shirin; Fahimzad, Alireza; Naddaf, Amir; Tavassoli, Sara

2015-12-01

The aim of this study was to evaluate the antibiotic susceptibility of Group A streptococcus (GAS) to antibiotics usually used in Iran for treatment of GAS pharyngitis in children. From 2011 to 2013, children 3-15 years of age with acute tonsillopharyngitis who attended Mofid Children's Hospital clinics and emergency ward and did not meet the exclusion criteria were enrolled in a prospective study in a sequential manner. The isolates strains from throat culture were identified as GAS by colony morphology, gram staining, beta hemolysis on blood agar, sensitivity to bacitracin, a positive pyrrolidonyl aminopeptidase (PYR) test result, and the presence of Lancefield A antigen determined by agglutination test. Antimicrobial susceptibility was identified by both disk diffusion and broth dilution methods. From 200 children enrolled in this study, 59 (30%) cases were culture positive for GAS. All isolates were sensitive to penicillin G. The prevalence of erythromycin, azithromycin, and clarithromycin resistance by broth dilution method was 33.9%, 57.6%, and 33.9%, respectively. Surprisingly, 8.4% of GAS strains were resistant to rifampin. In this study, 13.5% and 32.2% of the strains were resistant to clindamycin and ofloxacin, respectively. The high rate of resistance of GAS to some antibiotics in this study should warn physicians, especially in Iran, to use antibiotics restrictedly and logically to prevent the rising of resistance rates in future. It also seems that continuous local surveillance is necessary to achieve the best therapeutic option for GAS treatment.

Functional assessment of encapsulated citral for controlling necrotic enteritis in broiler chickens.

PubMed

Yang, Yuexi; Wang, Qi; Diarra, Moussa S; Yu, Hai; Hua, Yufei; Gong, Joshua

2016-04-01

Development of viable alternatives to antibiotics to control necrotic enteritis (NE) caused by Clostridium perfringensis becoming urgent for chicken production due to pessures on poultry producers to limit or stop the use of antibiotics in feed. We have previously identified citral as a potential alternative to antibiotics. Citral has strong antimicrobial activity and can be encasupsulated in a powder form for protection from loss during feed processing, storage, and intestinal delivery. In the present study, encapsulated citral was evaluated both in vitro and in vivo for its antimicrobial activity against C. perfringens Encapsulation did not adversely affect the antimicrobial activity of citral. In addition, encapsulated citral was superior to the unencapsulated form in retaining its antimicrobial activity after treatment with simulated gastrointestinal fluids and in the presence of chicken intestinal digesta. In addition, the higher antimicrobial activity of encapsulated citral was confirmed in digesta samples from broilers that had been gavaged with encapsulated or unencapsulated citral. In broilers infected with C. perfringens, the diets supplemented with encapsualted citral at both 250 and 650 μg/g significantly reduced intestinal NE lesions, which was comparable to the effect of bacitracin- and salinomycin-containing diets. However, supplementation with the encapsulated citral appeared to have no significant impact on the intestinal burden of Lactobacillus These data indicate that citral can be used to control NE in chickens after proper protection by encapsulation. © Crown copyright 2016.

Actinobacillus actinomycetemcomitans in Human Periodontal Disease: a Cross-Sectional Microbiological Investigation

PubMed Central

Slots, Jørgen; Reynolds, Homer S.; Genco, Robert J.

1980-01-01

Actinobacillus actinomycetemcomitans is a facultative gram-negative bacterium which has been associated with severe oral and nonoral infections. This study examined its occurrence in the oral cavities of 10 normal juveniles, 11 normal adults, 10 juvenile periodontitis patients, and 12 adult periodontitis patients. Four deep periodontal pockets and two normal periodontal sites were sampled in the diseased patients, and six normal periodontal sites were sampled in the healthy individuals. In all subjects samples were obtained from the cheek, tongue, and saliva. Samples from a total of 172 normal periodontal sites, 83 deep periodontal pockets, 42 cheek mucosae, 42 tongue dorsa, and 42 salivas were examined. Isolation was performed by using a medium for selective isolation of A. actinomycetemcomitans (Trypticase soy agar [BBL Microbiology Systems] supplemented with 10% serum and 75 μg of bacitracin per ml). The carrier rates were 20% for normal juveniles, 36% for normal adults, 50% for adult periodontitis patients, and 90% for juvenile periodontitis patients. A. actinomycetemcomitans was on average recovered in about fivefold-higher numbers from infected deep periodontal pockets than from infected normal subgingival areas. Samples of periodontal pockets generally contained 100-fold-more cells of A. actinomycetemcomitans than did samples of the cheek, tongue, and saliva. A. actinomycetemcomitans is commonly isolated from patients with juvenile periodontitis, often isolated from patients with adult periodontitis, and occasionally isolated from normal juveniles and adults. Its primary oral ecological niche appears to be dental plaque and periodontal pockets. PMID:6968718

Prevalence and Antibiogram Assessment of Staphylococcus aureus in Beef at Municipal Abattoir and Butcher Shops in Addis Ababa, Ethiopia

PubMed Central

Adugna, Feben; Pal, Mahendra

2018-01-01

Objective A cross-sectional study was conducted from October 2013 to April 2014 to determine the prevalence and antibiotic resistance of Staphylococcus aureus from beef of Addis Ababa Abattoir and butcher shops in Addis Ababa. Seven hundred sixty-eight swab samples were taken from the abattoir and butcher carcasses using a systematic random sampling. One hundred twenty swab samples were also taken from hooks, cutting tables, and knives from the abattoir. Staphylococcus aureus positive isolates were taken for antibiotic susceptibility test. A questionnaire survey was conducted in the abattoir and butcher workers to assess the hygienic practice and possible risk factors regarding the contamination of meat. Results The prevalence of S. aureus in the abattoir, butcher, cutting table, hook, and knife was 9.4%, 19.8%, 15%, 15%, and 22.5%, respectively. The prevalence of S. aureus in the knife and butcher was found to be 2.8 (OR = 2.8, CI = 1.2–6.4) and 2.4 (OR = 2.4, CI = 1.6–3.6) times that of the abattoir results (p < 0.01). The antimicrobial susceptibility testing was also conducted on 133 isolates of S. aureus using the disc diffusion susceptibility method. Bacitracin, neomycin, and methicillin were found to be 100% resistant to S. aureus. To avoid the presence of pathogenic Staphylococcus isolates, preventive measures using good hygienic practices during slaughtering and handling of the beef carcasses are recommended. PMID:29854759

Antibiotic resistance of lactic acid bacteria and Bifidobacterium spp. isolated from dairy and pharmaceutical products.

PubMed

D'Aimmo, Maria Rosaria; Modesto, Monica; Biavati, Bruno

2007-04-01

The outlines of antibiotic resistance of some probiotic microorganisms were studied. This study was conducted with the double purpose of verifying their ability to survive if they are taken simultaneously with an antibiotic therapy and to increase the selective properties of suitable media for the isolation of samples containing mixed bacterial populations. We isolated from commercial dairy and pharmaceutical products, 34 strains declared as probiotics, belonging to the genera Bifidobacterium and Lactobacillus, and 21 strains of starter culture bacteria. All the microorganisms have been compared by electrophoresis of the soluble proteins for the purpose of identifying them. A Multiplex-PCR with genus- and species-specific primers was used to detect for Bifidobacterium animalis subsp. lactis presence. All bifidobacteria were B. animalis subsp. lactis except one Bifidobacterium longum. Sometimes the identification showed that the used strain was not the one indicated on the label. The lactobacilli were Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus delbrueckii subsp. bulgaricus. The streptococci were all Streptococcus thermophilus. The minimal inhibitory concentration (MIC) of 24 common antibiotic substances has been valued by the broth microdilution method. All tested strains were susceptible to ampicillin, bacitracin, clindamycin, dicloxacillin, erytromycin, novobiocin, penicillin G, rifampicin (MIC(90) ranging from 0.01 to 4 microg/ml); resistant to aztreonam, cycloserin, kanamycin, nalidixic acid, polymyxin B and spectinomycin (MIC(90) ranging from 64 to >1000 microg/ml). The susceptibility to cephalothin, chloramphenicol, gentamicin, lincomycin, metronidazole, neomycin, paromomycin, streptomycin, tetracycline and vancomycin was variable and depending on the species.

Physiological Characteristics and Production of Folic Acid of Lactobacillus plantarum JA71 Isolated from Jeotgal, a Traditional Korean Fermented Seafood

PubMed Central

Lim, Sang-Dong

2014-01-01

Folic acid, one of the B group of vitamins, is an essential substance for maintaining the functions of the nervous system, and is also known to decrease the level of homocysteine in plasma. Homocysteine influences the lowering of the cognitive function in humans, and especially in elderly people. In order to determine the strains with a strong capacity to produce folic acid, 190 bacteria were isolated from various kinds of jeotgal and chungkuk-jang. In our test experiment, JA71 was found to contain 9.03μg/mL of folic acid after 24 h of incubation in an MRS broth. This showed that JA71 has the highest folic acid production ability compared to the other lactic acid bacteria that were isolated. JA71 was identified as Lactobacillus plantarum by the result of API carbohydrate fermentation pattern and 16s rDNA sequence. JA71 was investigated for its physiological characteristics. The optimum growth temperature of JA71 was 37℃, and the cultures took 12 h to reach pH 4.4. JA71 proved more sensitive to bacitracin when compared with fifteen different antibiotics, and showed most resistance to neomycin and vancomycin. Moreover, it was comparatively tolerant of bile juice and acid, and displayed resistance to Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus with restraint rates of 60.4%, 96.7%, and 76.2%, respectively. These results demonstrate that JA71 could be an excellent strain for application to functional products. PMID:26760752

SEROVARS AND ANTIMICROBIAL RESISTANCE OF Salmonella spp. ISOLATED FROM TURKEY AND BROILER CARCASSES IN SOUTHERN BRAZIL BETWEEN 2004 AND 2006

PubMed Central

PALMEIRA, Andre; dos SANTOS, Luciana Ruschel; BORSOI, Anderlise; RODRIGUES, Laura Beatriz; CALASANS, Max; do NASCIMENTO, Vladimir Pinheiro

2016-01-01

Salmonella spp. causes diseases in fowls, when species-specific serovars (Salmonella Pullorum and S.Gallinarum) are present in flocks, and public health problems, when non-typhoid serovars are isolated, as well as possible bacterial resistance induced by the preventive and therapeutic use of antimicrobials in animal production. This study describes the serovars and bacterial resistance of 280Salmonella spp. strains isolated from turkey and broiler carcasses in Southern Brazil between 2004 and 2006. SalmonellaEnteritidis was the most prevalent serovar (55.7%), followed by Heidelberg (5.0%), Agona (4.3%), Bredeney (3.9%), Hadar (3.2%), and Typhimurium (2.9%). Tennessee and S. Enterica subspecies enterica(O: 4.5) were isolated only in turkeys, and Hadar (18.6%) was the most prevalent serovar in this species. Antimicrobial susceptibility tests were performed in 178 isolates (43 from turkeys and 135 from broilers). All isolates were sensitive to amoxicillin + clavulanic acid, polymyxin B, ciprofloxacin, and norfloxacin, and were resistant to bacitracin and penicillin. Broiler carcass isolates showed resistance to nalidixic acid (48.9%), nitrofurantoin (34.3%), neomycin (9.6%), tetracycline (5.2%), and kanamycin (8.9%); and turkey carcass isolates were resistant to nalidixic acid (62.8%), tetracycline (34.9%), and neomycin (30.2%), with a significant difference in turkeys when compared to broiler carcass isolates. These results indicate the need for judicious use of antimicrobials in livestock production, given that the serovars identified are potential causes of food poisoning. PMID:27007562

Exploring the differences of antibiotic resistance genes profiles between river surface water and sediments using metagenomic approach.

PubMed

Jiang, Haoyu; Zhou, Renjun; Zhang, Mengdi; Cheng, Zhineng; Li, Jun; Zhang, Gan; Chen, Baowei; Zou, Shichun; Yang, Ying

2018-05-30

To better understand the potential genic communication and dissemination of antibiotic resistance genes (ARGs) in different environmental matrices, the differences of ARG profiles between river surface water and sediments were explored. Metagenomic analysis was applied to investigate the comprehensive ARG profiles in water and sediment samples collected from the highly human-impacted catchment of the Beijiang River and its river source. A total of 135 ARG subtypes belonging to 18 ARG types were identified. Generally, ARGs in surface water were more diverse and abundant than those in sediments. ARG profiles in the surface water and sediment samples were distinct from each other, but some ARGs were shared by the surface water and sediments. Results revealed that multidrug and bacitracin resistance genes were the predominant ARGs types in both surface water (0.30, 0.17 copies/cell) and sediments (0.19, 0.15 copies/cell). 73 ARG subtypes were shared by the water and sediment samples and had taken over 90% of the total detected ARG abundance. Most of the shared ARGs are resistant to the clinically relevant antibiotics. Furthermore, significant correlations between the ARGs and 21 shared genera or mobile genetic elements (MGEs) (plasmids and integrons) were found in surface water and sediments, suggesting the important role of genera or MGEs in shaping ARGs profiles, propagation and distribution. These findings provide deeper insight into mitigating the propagation of ARGs and the associated risks to public health. Copyright © 2018 Elsevier Inc. All rights reserved.

MALDI-TOF mass spectrometry-based identification of group A Streptococcus isolated from areas of the 2011 scarlet fever outbreak in china.

PubMed

Xiao, Di; You, Yuanhai; Bi, Zhenwang; Wang, Haibin; Zhang, Yongchan; Hu, Bin; Song, Yanyan; Zhang, Huifang; Kou, Zengqiang; Yan, Xiaomei; Zhang, Menghan; Jin, Lianmei; Jiang, Xihong; Su, Peng; Bi, Zhenqiang; Luo, Fengji; Zhang, Jianzhong

2013-03-01

There was a dramatic increase in scarlet fever cases in China from March to July 2011. Group A Streptococcus (GAS) is the only pathogen known to cause scarlet fever. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) coupled to Biotyper system was used for GAS identification in 2011. A local reference database (LRD) was constructed, evaluated and used to identify GAS isolates. The 75 GAS strains used to evaluate the LRD were all identified correctly. Of the 157 suspected β-hemolytic strains isolated from 298 throat swab samples, 127 (100%) and 120 (94.5%) of the isolates were identified as GAS by the MALDI-TOF MS system and the conventional bacitracin sensitivity test method, respectively. All 202 (100%) isolates were identified at the species level by searching the LRD, while 182 (90.1%) were identified by searching the original reference database (ORD). There were statistically significant differences with a high degree of credibility at species level (χ(2)=6.052, P<0.05 between the LRD and ORD). The test turnaround time was shortened 36-48h, and the cost of each sample is one-tenth of the cost of conventional methods. Establishing a domestic database is the most effective way to improve the identification efficiency using a MALDI-TOF MS system. MALDI-TOF MS is a viable alternative to conventional methods and may aid in the diagnosis and surveillance of GAS. Copyright © 2013 Elsevier B.V. All rights reserved.

Simultaneous determination of eight cyclopolypeptide antibiotics in feed by high performance liquid chromatography coupled with evaporation light scattering detection.

PubMed

Song, Xuqin; Xie, Jingmeng; Zhang, Meiyu; Zhang, Yingxia; Li, Jiufeng; Huang, Qiwen; He, Limin

2018-02-15

A high throughput, reliable and reproducible analysis strategy based on high performance liquid chromatography combined to evaporative light scattering detector (HPLC-ELSD) was developed for simultaneous determination of eight cyclopolypeptide antibiotics including vancomycin, polymyxin B (polymyxin B1 and polymyxin B2), polymyxin E (colistin A and colistin B), teicoplanin, bacitracin A, daptomycin and virginiamycin M1 in animal Feed. Feed samples were extracted with methanol-2% formic acid aqueous solution, followed by a solid-phase extraction step using a HLB cartridge. Under the optimum chromatographic conditions and ELSD parameters, target compounds were separated well on a short column filled with biphenyl stationary phase. The method was developed in accordance with pig complete feed and then extended to detect polypeptide antibiotics in piglet premix, pig feed additive, poultry complete feed and fattening pig premix. The results showed that logarithmic calibration curves of eight analytes were linear (r 2  > 0.99) within the concentration range of 5-200 mg mL -1 . The developed method provided good accuracy and precision for quantification of eight polypeptides in five kinds of feeds with recoveries ranging from 72.0% to 105.4% with relative standard deviations <9.5%. The limits of detection ranged from 2 to 5 mg kg -1 . Finally, the method was successfully applied to analyze polypeptide antibiotics in commercial feed. Copyright © 2018 Elsevier B.V. All rights reserved.

Fate and transport of antimicrobials and antimicrobial resistance genes in soil and runoff following land application of swine manure slurry.

PubMed

Joy, Stacey R; Bartelt-Hunt, Shannon L; Snow, Daniel D; Gilley, John E; Woodbury, Bryan L; Parker, David B; Marx, David B; Li, Xu

2013-01-01

Due to the use of antimicrobials in livestock production, residual antimicrobials and antimicrobial resistance genes (ARGs) could enter the environment following the land application of animal wastes and could further contaminate surface and groundwater. The objective of this study was to determine the effect of various manure land application methods on the fate and transport of antimicrobials and ARGs in soil and runoff following land application of swine manure slurry. Swine manure slurries were obtained from facilities housing pigs that were fed chlortetracyline, tylosin or bacitracin and were land applied via broadcast, incorporation, and injection methods. Three rainfall simulation tests were then performed on amended and control plots. Results show that land application methods had no statistically significant effect on the aqueous concentrations of antimicrobials in runoff. However, among the three application methods tested broadcast resulted in the highest total mass loading of antimicrobials in runoff from the three rainfall simulation tests. The aqueous concentrations of chlortetracyline and tylosin in runoff decreased in consecutive rainfall events, although the trend was only statistically significant for tylosin. For ARGs, broadcast resulted in significantly higher erm genes in runoff than did incorporation and injection methods. In soil, the effects of land application methods on the fate of antimicrobials in top soil were compound specific. No clear trend was observed in the ARG levels in soil, likely because different host cells may respond differently to the soil environments created by various land application methods.

Antimicrobial capacity of Aloe vera and propolis dentifrice against Streptococcus mutans strains in toothbrushes: an in vitro study.

PubMed

Bertolini, Patrícia Fernanda Roesler; Biondi Filho, Oswaldo; Pomilio, Arnaldo; Pinheiro, Sérgio Luiz; Carvalho, Meghi Silva de

2012-02-01

This study evaluated in vitro the efficiency of Aloe vera and propolis dentifrice on reducing the contamination of toothbrush bristles by a standard strain of Streptococcus mutans (ATCC 25175; SM), after toothbrushing. Fifteen sterile toothbrushes were randomly divided into 5 toothbrushing groups: I (negative control): without dentifrice; II: with fluoridated dentifrice; III: with triclosan and gantrez dentifrice; IV (positive control): without dentifrice and irrigation with 10 mL of 0.12% chlorhexidine gluconate; V: with Aloe vera and propolis dentifrice. In each group, 1 sterile bovine tooth was brushed for 1 min, where the toothbrush bristles were contaminated with 25 µL of SM. After toothbrushing, the bristles were stored in individual test tubes with 3 mL of BHI under anaerobiosis of 37°C for 48 h. Then, they were seeded with sterile swab in triplicate in the Mitis salivarius - Bacitracin culture medium. The samples were kept under anaerobiosis of 37°C for 48 h. Scores were used to count the number of colony forming units (cfu). The results were submitted to the Mann-Whitney statistical test at 5% significance level. There was statistically significant difference (p<0.05) for the reduction of bristle contamination comparing groups II, III, IV and V to group I. It may be stated that after toothbrushing, the Aloe vera and propolis dentifrice reduced the contamination of toothbrush bristles by SM, without differentiation from the other chemical agents used.

Comparing the efficacy of xylitol-containing and conventional chewing gums in reducing salivary counts of Streptococcus mutans: An in vivo study

PubMed Central

Haghgoo, Rosa; Afshari, Elahe; Ghanaat, Tahere; Aghazadeh, Samaneh

2015-01-01

Objective: Dental caries is among the most common chronic diseases in humans. Streptococcus mutans is generally responsible for most cases of dental caries. The present study sought to compare the effects of xylitol-containing and conventional chewing gums on salivary levels of S. mutans. Materials and Methods: This study adopted a crossover design. Two type of chewing gums (one containing 70% xylitol and approved by the Iranian Dental Association, and another containing sucrose) were purchased. The participants were 32 individuals aged 18–35 years whose oral hygiene was categorized as moderate or poor based on a caries risk assessment table. Salivary levels of S. mutans were measured at baseline, after the first and second phases of chewing gums, and after the washout period. The measurements were performed on blood agar and mitis salivarius-bacitracin agar (MSBA). Pairwise comparisons were then used to analyze the collected data. Results: Salivary levels of S. mutans in both groups were significantly higher during the two stages of chewing gum than in the washout period or baseline. Moreover, comparisons between the two types of gums suggested that chewing xylitol-containing gums led to greater reductions in S. mutans counts. This effect was more apparent in subjects with poor oral hygiene than in those with moderate oral hygiene. Conclusions: Xylitol-containing chewing gums are more effective than conventional gums in reducing salivary levels of S. mutans in individuals with poor–moderate oral hygiene. PMID:26942114

Inhibitors of peptidases: how they influence the biological activities of substance P, neurokinins, kinins and angiotensins in isolated vessels.

PubMed

Rouissi, N; Nantel, F; Drapeau, G; Rhaleb, N E; Dion, S; Regoli, D

1990-01-01

Myotropic effects of various peptides were measured in three isolated vessels, the dog carotid artery, the rabbit pulmonary artery and the rat portal vein in the absence and in presence of several peptidase inhibitors, in order to evaluate the interference by metabolism with the peptides' biological activities. After adequate controls, captopril (4.6 x 10(-6) mol/l), thiorphan (1.0 x 10(-6) mol/l), phosphoramidon (4.6 x 10(-6) mol/l), chymostatin (1 mg/l), bestatin (8.1 x 10(-6) mol/l) or bacitracin (1.4 x 10(-5) mol/l) were left in contact with the tissues for 20-40 min to inhibit tissue peptidases before measuring again the biological effects of the various peptides. In some experiments, mergetpa (5.4 x 10(-6) mol/l) was used. All peptidase inhibitors were inactive on their own and only captopril potentiated the effects of substance P, neurokinins, bradykinin and inhibited angiotensin I in two preparations, the dog carotid artery, the rat portal vein, and, excluding bradykinin, also in the rabbit pulmonary artery. Captopril and thiorphan significantly potentiated the maximal response of the rat portal vein to substance P and mergetpa inhibited completely the effect of bradykinin on the rabbit pulmonary artery. The present findings suggest that the most active proteolytic enzyme interfering with the biological effects of vasoactive peptides on three isolated vessels is the angiotensin-converting enzyme (kininase II).

Responses of Haloarchaea to Simulated Microgravity

NASA Astrophysics Data System (ADS)

Dornmayr-Pfaffenhuemer, Marion; Legat, Andrea; Schwimbersky, Karin; Fendrihan, Sergiu; Stan-Lotter, Helga

2011-04-01

Various effects of microgravity on prokaryotes have been recognized in recent years, with the focus on studies of pathogenic bacteria. No archaea have been investigated yet with respect to their responses to microgravity. For exposure experiments on spacecrafts or on the International Space Station, halophilic archaea (haloarchaea) are usually embedded in halite, where they accumulate in fluid inclusions. In a liquid environment, these cells will experience microgravity in space, which might influence their viability and survival. Two haloarchaeal strains, Haloferax mediterranei and Halococcus dombrowskii, were grown in simulated microgravity (SMG) with the rotary cell culture system (RCCS, Synthecon). Initially, salt precipitation and detachment of the porous aeration membranes in the RCCS were observed, but they were avoided in the remainder of the experiment by using disposable instead of reusable vessels. Several effects were detected, which were ascribed to growth in SMG: Hfx. mediterranei's resistance to the antibiotics bacitracin, erythromycin, and rifampicin increased markedly; differences in pigmentation and whole cell protein composition (proteome) of both strains were noted; cell aggregation of Hcc. dombrowskii was notably reduced. The results suggest profound effects of SMG on haloarchaeal physiology and cellular processes, some of which were easily observable and measurable. This is the first report of archaeal responses to SMG. The molecular mechanisms of the effects induced by SMG on prokaryotes are largely unknown; haloarchaea could be used as nonpathogenic model systems for their elucidation and in addition could provide information about survival during lithopanspermia (interplanetary transport of microbes inside meteorites).

Development and evaluation of a suppository formulation containing Lactobacillus and its application in vaginal diseases.

PubMed

Kale, Vinita V; Trivedi, Rashmi V; Wate, Sanjay P; Bhusari, Kishor P

2005-11-01

Lactobacillus has long been considered the protective flora in the vagina that displaces and kills vaginal pathogens. Lactic acid, H2O2, and antibacterial agents such as lactocin and bacitracin produced by Lactobacillus act against the vaginal pathogens. The first objective of this research was to develop a local application pharmaceutical formulation of a vaginal suppository containing lyophilized culture of Lactobacillus. The second objective was to establish its in vivo performance by developing in vitro methods of evaluation. Lyophilized culture of Lactobacillus sporogenes was selected for this study. Three formulations of the suppositories were prepared by the molding method. Formulations I, II, and III contained cocoa butter, glycerinated gelatin, and PEG 1000 base, respectively. The prepared suppositories were characterized for physical properties. Assembly to simulate the application site was designed. Methods to evaluate the viability, production of lactic acid, and H2O2 produced by the released Lactobacillus at the application site were developed and the antagonistic activity was demonstrated. From the physical characteristics of the suppository formulations, the glycerinated gelatin suppository (formulation II) containing lyophilized Lactobacillus was found to be satisfactory. The developed assembly was satisfactory in simulating the application site. The Lactobacillus released was viable and exhibited the production of lactic acid, hydrogen peroxide, and antagonistic activity against the uropathogen. The suppository formulation containing Lactobacillus and the methods of its evaluation were successfully developed in this research work and have several applications in the vaginal diseases of women.

Systemic Contact Dermatitis.

PubMed

Aquino, Marcella; Rosner, Greg

2018-05-15

Systemic contact dermatitis (SCD) traditionally refers to a skin condition where an individual who is cutaneously sensitized to an allergen will subsequently react to that same allergen or a cross reacting allergen via a different route. It occurs to allergens including metals, medications, and foods. The exact pathophysiology underlying this disease remains unknown, although it appears to be mediated by type 4 hypersensitivity reactions and possibly type 3 hypersensitivity reactions. The p-I concept (pharmacologic interaction with immunoreceptors) hypothesized that drugs are able to bind directly to a T cell receptor without first being presented by MHC (major histocompatibility complex) molecules and without prior metabolism, which would help explain why SCD can be seen on first exposure to medications. Nomenclature remains a challenge as SCD can be subcategorized using terms such as ACDS (allergic contact dermatitis syndrome) and its four clinical stages, Baboon syndrome, and SDRIFE (symmetrical drug-related intertriginous and flexural exanthema), which share many overlapping features. Food allergens may be responsible for uncontrolled or persistent symptoms in patients with contact dermatitis who do not respond to topical avoidance. With medications, symptoms may be induced by topical application versus systemic administration. Patch testing (PT) may be beneficial in diagnosing SCD caused by metals and many topical medications including corticosteroids, antimicrobials (ampicillin, bacitracin, erythromycin, neomycin, nystatin), NSAIDs (diclofenac, ibuprofen), anesthetics, and antihistamines (chlorphenamine, piperazine). Current treatment options include topical steroids and oral antihistamines for symptom relief and dietary avoidance to causative foods or metals.

Clonal structure of Streptococcus sanguinis strains isolated from endocarditis cases and the oral cavity.

PubMed

Do, T; Gilbert, S C; Klein, J; Warren, S; Wade, W G; Beighton, D

2011-10-01

A collection of Streptococcus sanguinis strains from patients with endocarditis (n = 21) and from the oral cavity (n = 34) was subjected to a multi-locus sequence typing analysis using seven housekeeping genes, carbamoyl-phosphate synthetase (carB), Co/Zn/Cd efflux system component (czcD), d-alanyl-d-alanine ligase (ddl), DNA polymerase III (dnaX), glucose-6-phosphate dehydrogenase (gdh), DNA-directed RNA polymerase, beta subunit (rpoB) and superoxide dismutase (sodA). The scheme was expanded by the inclusion of two the putative virulence genes, bacitracin-resistance protein (bacA) and saliva-binding protein (ssaB), to increase strain discrimination. Extensive intra-species recombination was apparent in all genes but inter-species recombination was also apparent with strains apparently harbouring gdh and ddl from unidentified sources and one isolate harboured a sodA allele apparently derived from Streptococcus oralis. The recombination/mutation ratio for the concatenated housekeeping gene sequences was 1.67 (95% confidence limits 1.25-2.72) and for the two virulence genes the r/m ratio was 3.99 (95% confidence limits 1.61-8.72); recombination was the major driver for genetic variation. All isolates were distinct and the endocarditis strains did not form distinct sub-clusters when the data were analysed using ClonalFrame. These data support the widely held opinion that infecting S. sanguinis strains are opportunistic human pathogens. © 2011 John Wiley & Sons A/S.

Antibiotic resistome in a large-scale healthy human gut microbiota deciphered by metagenomic and network analyses.

PubMed

Feng, Jie; Li, Bing; Jiang, Xiaotao; Yang, Ying; Wells, George F; Zhang, Tong; Li, Xiaoyan

2018-01-01

The human gut microbiota is an important reservoir of antibiotic resistance genes (ARGs). A metagenomic approach and network analysis were used to establish a comprehensive antibiotic resistome catalog and to obtain co-occurrence patterns between ARGs and microbial taxa in fecal samples from 180 healthy individuals from 11 different countries. In total, 507 ARG subtypes belonging to 20 ARG types were detected with abundances ranging from 7.12 × 10 -7 to 2.72 × 10 -1 copy of ARG/copy of 16S-rRNA gene. Tetracycline, multidrug, macrolide-lincosamide-streptogramin, bacitracin, vancomycin, beta-lactam and aminoglycoside resistance genes were the top seven most abundant ARG types. The multidrug ABC transporter, aadE, bacA, acrB, tetM, tetW, vanR and vanS were shared by all 180 individuals, suggesting their common occurrence in the human gut. Compared to populations from the other 10 countries, the Chinese population harboured the most abundant ARGs. Moreover, LEfSe analysis suggested that the MLS resistance type and its subtype 'ermF' were representative ARGs of the Chinese population. Antibiotic inactivation, antibiotic target alteration and antibiotic efflux were the dominant resistance mechanism categories in all populations. Procrustes analysis revealed that microbial phylogeny structured the antibiotic resistome. Co-occurrence patterns obtained via network analysis implied that 12 species might be potential hosts of 58 ARG subtypes. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Improved agar diffusion method for detecting residual antimicrobial agents.

PubMed

Tsai, C E; Kondo, F

2001-03-01

The improved agar diffusion method for determination of residual antimicrobial agents was investigated, and the sensitivities of various combinations of test organisms and assay media were determined using 7 organisms, 5 media, and 31 antimicrobial agents. Bacillus stearothermophilus and synthetic assay medium (SAM) showed the greatest sensitivity for screening penicillins (penicillin G and ampicillin). The combination of Bacillus subtilis and minimum medium (MM) was the most sensitive for tetracyclines (oxytetracycline and chlortetracycline), B. stearothermophilus and SAM or Micrococcus luteus and Mueller-Hinton agar (MHA) for detecting tylosin and erythromycin, B. subtilis and MHA for aminoglycosides (streptomycin, kanamycin, gentamicin, and dihydrostreptomycin), B. stearothermophilus and SAM for polyethers (salinomycin and lasalocid), and B. subtilis and MM or Clostridium perfringens and GAM for polypeptides (thiopeptin, enramycin, virginiamycin, and bacitracin). However, gram-negative bacterium Escherichia coli ATCC 27166 and MM were better for screening for colistin and polymixin-B. For detecting the synthetic drugs tested, the best combination was B. subtilis and MM for sulfonamides, E. coli 27166 and MM for quinolones (oxolinic acid and nalidixic acid), B. subtilis and MM for furans (furazolidone), and the bioluminescent bacterium Photobacterium phosphoreum and luminescence assay medium for chloramphenicol and oxolinic acid. The results showed that the use of four assay plates, B. stearothermophilus and SAM, B. subtilis and MM, M. luteus and MHA, and E. coli 27166 and MM, was superior to the currently available techniques for screening for residual antimicrobial agents in edible animal tissues.

Chemical characterization of the glycated myofibrillar proteins from grass carp (Ctenopharyngodon idella) and their impacts on the human gut microbiota in vitro fermentation.

PubMed

Han, Kaining; Yao, Ye; Dong, Shiyuan; Jin, Sun; Xiao, Hang; Wu, Haohao; Zeng, Mingyong

2017-03-22

In this study, the chemical characterization of glycoconjugates of myofibrillar proteins from grass carp conjugated with glucose via Maillard reaction for up to 24 h of dry-heating was investigated, and their impacts on the microbial community in vitro human fecal fermentation were firstly evaluated by high-throughput sequencing technologies. The glycation greatly increased the furosine levels in glycoconjugates, which reached the maximum level (2.87 ± 0.08 mg per 100 mg protein) for 9 h of heating, and resulted in the structural changes of myofibrillar proteins based on the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared spectroscopy (FTIR) analysis. Size-exclusion chromatography (SEC) analysis of digested glycoconjugates showed that the gradually increased proportion between 1423 Da (bacitracin)-12 588 Da (cytochrome C) with the prolongation of heating time, suggesting that glycation decreased the digestibility of myofibrillar proteins. Furthermore, glycoconjugates with a higher level of Amadori products and lower browning intensity enhanced fecal microbiota diversity based on species-level phylotypes. The production of butyrate in fermentation of digested glycoconjugates was affected by the glycation extent of myofibrillar proteins, and significantly and positively correlated with Mitsuokella, Lachnospiraceae_UCG-004, Sutterella, Salinimicrobium, Fodinibius and Nitriliruptor (p < 0.05), but negatively correlated with Enterococcus, Dorea (p < 0.05), Escherichia-Shigella and Phascolarctobacterium (p < 0.01). Our findings demonstrated that the glycation of myofibrillar proteins could have potentially positive effects to intestinal health.

Bacterial keratitis: a prospective clinical and microbiological study

PubMed Central

Schaefer, F.; Bruttin, O.; Zografos, L.; Guex-Crosier, Y.

2001-01-01

AIM—To define the clinical and microbiological profile of bacterial keratitis at the Jules Gonin Eye Hospital and to test the in vitro bacterial resistance.
METHODS—Patients presenting with bacterial keratitis were prospectively followed; clinical features (age, risk factors, visual acuity) and response to therapy were analysed. Bacteriological profile was determined and the sensitivity/resistance of isolated strains were tested towards 12 ocular antibiotics (NCCLS disc diffusion test).
RESULTS—85 consecutive patients (mean age 44.3 (SD 20.7) years) were prospectively enrolled from 1 March 1997 to 30 November 1998. The following risk factors were identified: contact lens wear, 36%; blepharitis, 21%; trauma, 20%; xerophthalmia, 15%; keratopathies, 8%; and eyelid abnormalities, 6%. The most commonly isolated bacteria were Staphylococcus epidermidis, 40%; Staphylococcus aureus, 22%; Streptococcus pneumoniae, 8%; others Streptococcus species, 5%; Pseudomonas, 9%; Moraxella and Serratia marcescens, 5% each; Bacillus, Corynebacterium, Alcaligenes xyloxidans, Morganella morganii, and Haemophilus influenza, 1% each. 1-15% of strains were resistant to fluoroquinolones, 13-22% to aminoglycosides, 37% to cefazolin, 18% to chloramphenicol, 54% to polymyxin B, 51% to fusidic acid, and 45% to bacitracin. Five of the 85 patients (5.8%) had a poor clinical outcome with a visual loss of one or more lines of visual acuity.
CONCLUSION—Fluoroquinolones appear to be the therapy of choice for bacterial keratitis, but, based upon these in vitro studies, some strains may be resistant.

 PMID:11423460

Metagenomic analysis of antibiotic resistance genes (ARGs) during refuse decomposition.

PubMed

Liu, Xi; Yang, Shu; Wang, Yangqing; Zhao, He-Ping; Song, Liyan

2018-04-12

Landfill is important reservoirs of residual antibiotics and antibiotic resistance genes (ARGs), but the mechanism of landfill application influence on antibiotic resistance remains unclear. Although refuse decomposition plays a crucial role in landfill stabilization, its impact on the antibiotic resistance has not been well characterized. To better understand the impact, we studied the dynamics of ARGs and the bacterial community composition during refuse decomposition in a bench-scale bioreactor after long term operation (265d) based on metagenomics analysis. The total abundances of ARGs increased from 431.0ppm in the initial aerobic phase (AP) to 643.9ppm in the later methanogenic phase (MP) during refuse decomposition, suggesting that application of landfill for municipal solid waste (MSW) treatment may elevate the level of ARGs. A shift from drug-specific (bacitracin, tetracycline and sulfonamide) resistance to multidrug resistance was observed during the refuse decomposition and was driven by a shift of potential bacteria hosts. The elevated abundance of Pseudomonas mainly contributed to the increasing abundance of multidrug ARGs (mexF and mexW). Accordingly, the percentage of ARGs encoding an efflux pump increased during refuse decomposition, suggesting that potential bacteria hosts developed this mechanism to adapt to the carbon and energy shortage when biodegradable substances were depleted. Overall, our findings indicate that the use of landfill for MSW treatment increased antibiotic resistance, and demonstrate the need for a comprehensive investigation of antibiotic resistance in landfill. Copyright © 2018. Published by Elsevier B.V.

Characterization of multiple antibiotic resistance of culturable microorganisms and metagenomic analysis of total microbial diversity of marine fish sold in retail shops in Mumbai, India.

PubMed

Naik, Onkar A; Shashidhar, Ravindranath; Rath, Devashish; Bandekar, Jayant R; Rath, Archana

2018-03-01

Marine fish species were analyzed for culturable and total metagenomic microbial diversity, antibiotic resistance (AR) pattern, and horizontal gene transfer in culturable microorganisms. We observed a high AR microbial load of 3 to 4 log CFU g -1 . Many fish pathogens like Providencia, Staphylococcus, Klebsiella pneumoniae, Enterobacter, Vagococcus, and Aeromonas veronii were isolated. Photobacterium and Vibrio were two major fish and human pathogens which were identified in the fish metagenome. Other pathogens that were identified were Shewanella, Acinetobacter, Psychrobacter, and Flavobacterium. Most of these pathogens were resistant to multiple antibiotics such as erythromycin, kanamycin, neomycin, streptomycin, penicillin, cefotaxime, bacitracin, rifampicin, trimethoprim, ciprofloxacin, and doxycycline with a high multiple antibiotic resistance index of 0.54-0.77. The fish microflora showed high prevalence of AR genes like bla TEM , Class I integron, tetA, aph(3')-IIIa, ermB, aadA, and sul1. Nineteen of 26 AR isolates harbored Class I integrons showing high co-resistance to trimethoprim, kanamycin, doxycycline, and cefotaxime. Mobile R-plasmids from 6 of the 12 AR pathogens were transferred to recipient E. coli after conjugation. The transconjugants harbored the same R-plasmid carrying bla CTX-M , dfr1, tetA, bla TEM , and cat genes. This study confirms that fish is a potential carrier of AR pathogens which can enter the human gut via food chain. To the best of our knowledge, this is the first study in the Indian subcontinent reporting a direct evidence of spread of AR pathogens to humans from specific marine fish consumption.

Effect of Probiotic Yogurt and Xylitol-Containing Chewing Gums on Salivary S Mutans Count.

PubMed

Ghasemi, Elnaz; Mazaheri, Romina; Tahmourespour, Arezoo

In addition to improving gastrointestinal health and intestinal microflora, probiotic bacteria have been recently suggested to decrease cariogenic agents in the oral cavity. The aim of this study was to investigate the effects of probiotic yogurt and xylitol-containing chewing gums on reducing salivary Streptococcus mutans levels. This randomized clinical trial recruited 50 female students with over 10 5 colony forming units S. mutans per milliliter of their saliva. The participants were randomly allocated to two equal groups to receive either probiotic yogurt containing Lactobacillus acidophilus ATCC 4356 andBifidobacteriumbifidum ATCC 29521 (200 g daily) or xylitol-containing chewing gums (two gums three times daily after each meal; total xylitol content: 5.58 g daily) for three weeks. At baseline and one day, two weeks, and four weeks after the interventions, saliva samples were cultured on mitis-salivarius-bacitracin agar and salivary S. mutans counts were determined. Data were analyzed with independent t-tests, analysis of variance, and Fisher's least significant difference test. In both groups, S. mutans counts on the first day, second week, and fourth weeks after the intervention were significantly lower than baseline values (P < 0.05). The greatest level of reduction in both groups was observed in the second week after the intervention. Moreover, although the reduction was greater in probiotic yogurt consumers, the difference between the two groups was not statistically significant. Probiotic yogurt and xylitol-containing chewing gums seem to be as effective in reduction of salivary S. mutans levels. Their constant long-term consumption is thus recommended to prevent caries.

Identification of three protein disulfide isomerase members from Haemaphysalis longicornis tick.

PubMed

Liao, Min; Hatta, Takeshi; Umemiya, Rika; Huang, Penglong; Jia, Honglin; Gong, Haiyan; Zhou, Jinlin; Nishikawa, Yoshifumi; Xuan, Xuenan; Fujisaki, Kozo

2007-07-01

Three genes encoding putative protein disulfide isomerase (PDI) were isolated from the Haemaphysalis longicornis EST database and designed as HlPDI-1, HlPDI-2, and HlPDI-3. All three PDI genes contain two typical PDI active sites CXXC and encode putative 435, 499, and 488 amino acids, respectively. The recombinant proteins expressed in Escherichia coli all show PDI activities, and the activities were inhibited by a PDI-specific inhibitor, zinc bacitracin. Western blot analysis and real-time PCR revealed that three HlPDIs were present in all the developmental stages of the tick as well as in the midgut, salivary glands, ovary, hemolymph, and fatbody of adult female ticks, but the three genes were expressed at the highest level in the egg stage. HlPDI-1 is expressed primarily in the ovary and secondarily in the salivary glands. HlPDI-2 and HlPDI-3 are expressed primarily in the salivary gland, suggesting that the PDI genes are important for tick biology, especially for egg development, and that they play distinct roles in different tissues. Blood feeding induced significantly increased expression of HlPDI-1 and HlPDI-3 in both partially fed nymphs and adults. Babesia gibsoni-infected larval ticks expressed HlPDI-1 and HlPDI-3 2.0 and 4.0 times higher than uninfected normal larval ticks, respectively. The results indicate that HlPDI-1 and HlPDI-3 might be involved in tick blood feeding and Babesia parasite infection in ticks.

The Crystal Structure of a Quercetin 2,3-Dioxygenase from Bacillus subtilis Suggests Modulation of Enzyme Activity by a Change in the Metal Ion at the Active Site(s)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gopal, B.; Madan, Lalima L.; Betz, Stephen F.

2010-11-10

Common structural motifs, such as the cupin domains, are found in enzymes performing different biochemical functions while retaining a similar active site configuration and structural scaffold. The soil bacterium Bacillus subtilis has 20 cupin genes (0.5% of the total genome) with up to 14% of its genes in the form of doublets, thus making it an attractive system for studying the effects of gene duplication. There are four bicupins in B. subtilis encoded by the genes yvrK, yoaN, yxaG, and ywfC. The gene products of yvrK and yoaN function as oxalate decarboxylases with a manganese ion at the active site(s),more » whereas YwfC is a bacitracin synthetase. Here we present the crystal structure of YxaG, a novel iron-containing quercetin 2,3-dioxygenase with one active site in each cupin domain. Yxag is a dimer, both in solution and in the crystal. The crystal structure shows that the coordination geometry of the Fe ion is different in the two active sites of YxaG. Replacement of the iron at the active site with other metal ions suggests modulation of enzymatic activity in accordance with the Irving-Williams observation on the stability of metal ion complexes. This observation, along with a comparison with the crystal structure of YvrK determined recently, has allowed for a detailed structure-function analysis of the active site, providing clues to the diversification of function in the bicupin family of proteins.« less

Cognitive Impairment by Antibiotic-Induced Gut Dysbiosis: Analysis of Gut Microbiota-Brain Communication

PubMed Central

Fröhlich, Esther E.; Farzi, Aitak; Mayerhofer, Raphaela; Reichmann, Florian; Jačan, Angela; Wagner, Bernhard; Zinser, Erwin; Bordag, Natalie; Magnes, Christoph; Fröhlich, Eleonore; Kashofer, Karl; Gorkiewicz, Gregor; Holzer, Peter

2016-01-01

Emerging evidence indicates that disruption of the gut microbial community (dysbiosis) impairs mental health. Germ-free mice and antibiotic-induced gut dysbiosis are two approaches to establish causality in gut microbiota-brain relationships. However, both models have limitations, as germ-free mice display alterations in blood-brain barrier and brain ultrastructure and antibiotics may act directly on the brain. We hypothesized that the concerns related to antibiotic-induced gut dysbiosis can only adequately be addressed if the effect of intragastric treatment of adult mice with multiple antibiotics on (i) gut microbial community, (ii) metabolite profile in the colon, (iii) circulating metabolites, (iv) expression of neuronal signaling molecules in distinct brain areas and (v) cognitive behavior is systematically investigated. Of the antibiotics used (ampicillin, bacitracin, meropenem, neomycin, vancomycin), ampicillin had some oral bioavailability but did not enter the brain. 16S rDNA sequencing confirmed antibiotic-induced microbial community disruption, and metabolomics revealed that gut dysbiosis was associated with depletion of bacteria-derived metabolites in the colon and alterations of lipid species and converted microbe-derived molecules in the plasma. Importantly, novel object recognition, but not spatial, memory was impaired in antibiotic-treated mice. This cognitive deficit was associated with brain region-specific changes in the expression of cognition-relevant signaling molecules, notably brain-derived neurotrophic factor, N-methyl-D-aspartate receptor subunit 2B, serotonin transporter and neuropeptide Y system. We conclude that circulating metabolites and the cerebral neuropeptide Y system play an important role in the cognitive impairment and dysregulation of cerebral signaling molecules due to antibiotic-induced gut dysbiosis. PMID:26923630

Characterization of Multi-Drug Resistant Enterococcus faecalis Isolated from Cephalic Recording Chambers in Research Macaques (Macaca spp.).

PubMed

Woods, Stephanie E; Lieberman, Mia T; Lebreton, Francois; Trowel, Elise; de la Fuente-Núñez, César; Dzink-Fox, Joanne; Gilmore, Michael S; Fox, James G

2017-01-01

Nonhuman primates are commonly used for cognitive neuroscience research and often surgically implanted with cephalic recording chambers for electrophysiological recording. Aerobic bacterial cultures from 25 macaques identified 72 bacterial isolates, including 15 Enterococcus faecalis isolates. The E. faecalis isolates displayed multi-drug resistant phenotypes, with resistance to ciprofloxacin, enrofloxacin, trimethoprim-sulfamethoxazole, tetracycline, chloramphenicol, bacitracin, and erythromycin, as well as high-level aminoglycoside resistance. Multi-locus sequence typing showed that most belonged to two E. faecalis sequence types (ST): ST 4 and ST 55. The genomes of three representative isolates were sequenced to identify genes encoding antimicrobial resistances and other traits. Antimicrobial resistance genes identified included aac(6')-aph(2"), aph(3')-III, str, ant(6)-Ia, tetM, tetS, tetL, ermB, bcrABR, cat, and dfrG, and polymorphisms in parC (S80I) and gyrA (S83I) were observed. These isolates also harbored virulence factors including the cytolysin toxin genes in ST 4 isolates, as well as multiple biofilm-associated genes (esp, agg, ace, SrtA, gelE, ebpABC), hyaluronidases (hylA, hylB), and other survival genes (ElrA, tpx). Crystal violet biofilm assays confirmed that ST 4 isolates produced more biofilm than ST 55 isolates. The abundance of antimicrobial resistance and virulence factor genes in the ST 4 isolates likely relates to the loss of CRISPR-cas. This macaque colony represents a unique model for studying E. faecalis infection associated with indwelling devices, and provides an opportunity to understand the basis of persistence of this pathogen in a healthcare setting.

Is There Still a Role for Irrigation and Debridement With Liner Exchange in Acute Periprosthetic Total Knee Infection?

PubMed

Duque, Andrés F; Post, Zachary D; Lutz, Rex W; Orozco, Fabio R; Pulido, Sergio H; Ong, Alvin C

2017-04-01

Periprosthetic joint infection (PJI) is an important cause of failure in total knee arthroplasty. Irrigation and debridement including liner exchange (I&D/L) success rates have varied for acute PJI. The purpose of this study is to present results of a specific protocol for I&D/L with retention of total knee arthroplasty components. Sixty-seven consecutive I&D/L patients were retrospectively evaluated. Inclusion criteria for I&D/L were as follows: fewer than 3 weeks of symptoms, no immunologic compromise, intact soft tissue sleeve, and well-fixed components. I&D/L consisted of extensive synovectomy; irrigation with 3 L each of betadine, Dakin's, bacitracin, and normal saline solutions; and exchange of the polyethylene component. Postoperatively, all patients were treated with intravenous antibiotics. Infection was considered eradicated if the wound healed without persistent drainage, there was no residual pain or evidence of infection. Forty-six patients (68.66%) had successful infection eradication regardless of bacterial strain. Those with methicillin-resistant Staphylococcus aureus (MRSA) had an 80% failure rate and those with Pseudomonas aeruginosa had a 66.67% failure rate. The success rate for bacteria other than MRSA and Pseudomonas was 85.25%. Our protocol for I&D/L was successful in the majority of patients who met strict criteria. We recommend that PJI patients with MRSA or P aeruginosa not undergo I&D/L and be treated with 2-stage revision. For nearly all other patients, our protocol avoids the cost and patient morbidity of a 2-stage revision. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of Cariogenic Bacteria

PubMed Central

Nishikawara, Fusao; Nomura, Yoshiaki; Imai, Susumu; Senda, Akira; Hanada, Nobuhiro

2007-01-01

Objectives The evaluation of Mutans streptococci (MS) is one of the index for caries risk. DentocultTM and CRTTM are commercial kits to detect and evaluate MS, conveniently. However, the evaluation of MS has also been carried out simply using an instruction manual. But the instruction manual is not easy to use for evaluation of MS. The aim of this study was to examine the utility of modified Mitis-Salivalius Bacitracin (MSB) agar medium compared with MSB agar medium and commercial kits, and to establish a convenient kit (mMSB-kit) using modified MSB agar. Methods The MS in stimulated saliva from 27 subjects were detected by MSB, modified MSB agar medium and commercial kits. Laboratory and clinically isolated strains of MS were similarly evaluated. The ratios of MS in detected bacteria were compared by ELISA. Results The scores using an mMSB-kit on the basis of modified MSB agar medium were tabulated. Saliva samples showed different levels of MS between culture methods and the commercial kit. Some samples which were full of MS were not detected by the commercial kit. The detection of MS by modified MSB agar medium and mMSB-kit were significantly higher when compared with MSB agar medium,CRTTM, (P< .01) and Dentocult SMTM (P<.05). Conclusion The sensitivity for detection of MS is higher for modified MSB agar medium when compared with MSB agar medium. The mMSB-kit can be used simply, and can be an important contributor for the evaluation of MS as a caries risk factor. PMID:19212495

Inhibition of serotonin release by bombesin-like peptides in rat hypothalamus in vitro.

PubMed

Saporito, M S; Warwick, R O

1989-01-01

We investigated the activity of bombesin (BN), neuromedin-C (NM-C) and neuromedin-B (NM-B) on serotonin (5-HT) release and reuptake in rat hypothalamus (HYP) in vitro. BN and NM-C but not NM-B (all 1 microM) decreased K+ evoked 3H-5-HT release from superfused HYP slices by 25%. Bacitracin (BCN, 2 micrograms/ml), a nonspecific peptidase inhibitor, reversed the inhibitory effect of BN on K+ evoked 3H-5-HT release. Phosphoramidon (PAN, 10 microM) an endopeptidase 24.11 inhibitor, abolished the inhibitory effect of BN, but not NM-C, on K+ evoked 3H-5-HT release. The peptidyl dipeptidase A inhibitor enalaprilat (ENP, 10 microM), enhanced both BN and NM-C inhibition of 3H-5-HT release. Bestatin (BST, 10 microM) had no effect on BN or NM-C inhibitory activity on 3H-5-HT release. Neither BN, NM-C nor NM-B affected reuptake of 3H-5-HT into HYP synaptosomes alone or in combination with any of the peptidase inhibitors, nor did these peptides alter the ability of fluoxetine to inhibit 3H-5-HT uptake. These data suggest: a) that BN-like peptides may alter neurotransmission in the HYP by acting presynaptically on the 5-HT release mechanism; b) a similarity in the structural requirements for the BN induced inhibition of 5-HT release and BN evoked thermoregulatory disturbances; and c) that peptidases may selectively augment or reduce pharmacologic activity of BN-like peptides upon CNS administration.

Development of a Selective Culture Medium for Primary Isolation of the Main Brucella Species▿

PubMed Central

De Miguel, M. J.; Marín, C. M.; Muñoz, P. M.; Dieste, L.; Grilló, M. J.; Blasco, J. M.

2011-01-01

Bacteriological diagnosis of brucellosis is performed by culturing animal samples directly on both Farrell medium (FM) and modified Thayer-Martin medium (mTM). However, despite inhibiting most contaminating microorganisms, FM also inhibits the growth of Brucella ovis and some B. melitensis and B. abortus strains. In contrast, mTM is adequate for growth of all Brucella species but only partially inhibitory for contaminants. Moreover, the performance of both culture media for isolating B. suis has never been established properly. We first determined the performance of both media for B. suis isolation, proving that FM significantly inhibits B. suis growth. We also determined the susceptibility of B. suis to the antibiotics contained in both selective media, proving that nalidixic acid and bacitracin are highly inhibitory, thus explaining the reduced performance of FM for B. suis isolation. Based on these results, a new selective medium (CITA) containing vancomycin, colistin, nystatin, nitrofurantoin, and amphotericin B was tested for isolation of the main Brucella species, including B. suis. CITA's performance was evaluated using reference contaminant strains but also field samples taken from brucella-infected animals or animals suspected of infection. CITA inhibited most contaminant microorganisms but allowed the growth of all Brucella species, to levels similar to those for both the control medium without antibiotics and mTM. Moreover, CITA medium was more sensitive than both mTM and FM for isolating all Brucella species from field samples. Altogether, these results demonstrate the adequate performance of CITA medium for the primary isolation of the main Brucella species, including B. suis. PMID:21270216

Release of antibiotics from collagen dressing.

PubMed

Grzybowski, J; Antos-Bielska, M; Ołdak, E; Trafny, E A

1997-01-01

Our new collagen dressing has been developed recently. Three types (A, B, and C) of the dressing were prepared in this study. Each type contained bacitracin, neomycin or colistin. The antibiotic was input into: i. collagen sponge (CS)--type A, ii. layer of limited hydrophobicity (LLH)--type B, and iii. into both CS and LLH layers--type C. The final concentration of the antibiotic that resulted from the loading level was 2 mg/cm2 for the dressings of type A and B and 4 mg/cm2 for the dressing of type C. The antibiotics were then extracted from the pieces of dressings for two days through dialysis membrane. Susceptibility of 54 bacterial strains (S. aureus, P. aeruginosa, and Acinetobacter) isolated from burn wounds were tested to the three antibiotics used for preparation of the dressings. The results of the study evidenced that efficiency of released of antibiotics into the extracts depended on the kind of antibiotic and on the type of dressing. The concentration of the antibiotics proved to be much higher than MIC90 values of the bacterial isolates tested in respect to their susceptibility. The dressing containing mixture of the three antibiotics in two layers--CS and LLH is now considered as potentially effective for care of infected wounds. It may be useful for the treatment of infected wounds or for profilaxis of contaminated wounds, ensuring: i. sufficient antimicrobial activity in wound, and ii. optimal wound environment for the presence of collagenic biomaterial on the damaged tissue.

Antibiotic resistance of Vibrio parahaemolyticus isolated from coastal seawater and sediment in Malaysia

NASA Astrophysics Data System (ADS)

Drais, Ashraf Abbas; Usup, Gires; Ahmad, Asmat

2016-11-01

Vibrio parahaemolyticus is widely recognized pathogenic Vibrio species due to numerous outbreaks and its' wide occurrence in the marine environment. A total of 50 Vibrio parahaemolyticus isolates were isolated from seawater and sediments in Malaysia were tested for sensitivity to 19 antibiotics using disc diffusion method. It was found that all isolates were resistant towards ampicillin (10 μg), penicillin (10 μg), methicillin (5 μg), and novobiocin (5 μg); but exhibit sensitivity to chloramphenicol (30 μg) and gentamicin (100 μg). The low percentage of sensitivity towards antibiotics was observed with the following antibiotics; amoxicillin 10μg (98%), fluconazole 25μg (98%), erythromycin 15 μg (92%), vancomycin 30 μg (92%), bacitracin 10 μg (84%), carbenicillin 100 μg (84%), cephalothin 30 μg (52%), nitrofurantion 200 μg (52%), ciprofloxacin 5 μg (40%), tetracycline 30 μg (20%), kanamycin 30 μg (10%), nalidixic acid 30 μg (10%) and streptomycin 20 μg (6%). Multiple antibiotic resistance (MAR) index was found to be 0.42-0.78. All the isolates were multi-resistant to these antibiotics. This indicates that the isolates originate from high-risk source of contamination where antibiotics are often used. Thus, there is a need for supervised use of antibiotics and frequent surveillance of V. parahaemolyticus strains for antimicrobial resistance. The presence of V. parahaemolyticus in coastal water with a high value of multiple antibiotic resistance indexes (MARI) can increase the risk of exposure to human and regular monitoring program for this potential human pathogenic bacterium is important.

[Studies for the development of novel anti-MRSA/VRE drugs].

PubMed

Hashizume, Hideki

2012-01-01

The widespread emergence of multidrug-resistant Gram-positive pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) is a high threat for human health. In the course of screening for active compounds against the above drug-resistant bacteria from microbial metabolites, we discovered three kinds of novel compounds designated tripropeptins, pargamicin, and amycolamicin. Tripropeptin C (TPPC), major component of tripropeptins, is the most promising compound because it is efficacious against MRSA and VRE both in vitro and in a mouse septicemia model, and shows no cross-resistance to available drugs including vancomycin. Studies of incorporation of radioactive macromolecular precursors and accumulation of UDP-MurNAc-pentapeptide in the cytoplasm in S. aureus Smith revealed that TPPC is a cell wall synthesis inhibitor. Antimicrobial activity of TPPC was weakened by addition of prenylpyrophosphates but not with prenylphosphates, UDP-linked sugars, or the pentapeptide of peptidoglycan. Direct interaction between TPPC and undecaprenyl pyrophosphate (C(55)-PP) was observed by mass spectrometry and thin layer chromatography, and TPPC inhibits C(55)-PP phosphatase, which plays a crucial role in peptidoglycan synthesis at an IC(50) of 0.03-0.1 µM in vitro. From the analysis of accumulation of lipid carrier-related compounds, TPPC caused accumulation of C(55)-PP in situ, leading to the accumulation of a glycine-added lipid intermediate, suggesting a distinct mode of action from that of clinically important drugs such as vancomycin, daptomycin, and bacitracin. TPPC might represent a promising novel class of antibiotic against MRSA and VRE infections.

Effect of peptidases on the ability of exogenous and endogenous neurokinins to produce neurokinin 1 receptor internalization in the rat spinal cord.

PubMed

Marvizon, Juan Carlos G; Wang, Xueren; Lao, Li-Jun; Song, Bingbing

2003-12-01

The ability of peptidases to restrict neurokinin 1 receptor (NK1R) activation by exogenously applied or endogenously released neurokinins was investigated by measuring NK1R internalization in rat spinal cord slices. Concentration-response curves for substance P and neurokinin A were obtained in the presence and absence of 10 microm thiorphan, an inhibitor of neutral endopeptidase (EC 3.4.24.11), plus 10 microm captopril, an inhibitor of dipeptidyl carboxypeptidase (EC 3.4.15.1). These inhibitors significantly decreased the EC50 of substance P to produce NK1R internalization from 32 to 9 nm, and the EC50 of neurokinin A from 170 to 60 nm. Substance P was significantly more potent than neurokinin A, both with and without these peptidase inhibitors. In the presence of peptidase inhibitors, neurokinin B was 10 times less potent than neurokinin A and 64 times less potent than substance P (EC50=573 nm). Several aminopeptidase inhibitors (actinonin, amastatin, bacitracin, bestatin and puromycin) failed to further increase the effect of thiorphan plus captopril on the NK1R internalization produced by 10 nm substance P. Electrical stimulation of the dorsal root produced NK1R internalization by releasing endogenous neurokinins. Thiorphan plus captopril increased NK1R internalization produced by 1 Hz stimulation, but not by 30 Hz stimulation. Therefore, NEN and DCP restrict NK1R activation by endogenous neurokinins when they are gradually released by low-frequency firing of primary afferents, but become saturated or inhibited when primary afferents fire at a high frequency.

Antimicrobial activity of Calendula officinalis, Camellia sinensis and chlorhexidine against the adherence of microorganisms to sutures after extraction of unerupted third molars.

PubMed

Faria, Raquel Lourdes; Cardoso, Lincoln Marcelo Lourenço; Akisue, Gokithi; Pereira, Cristiane Aparecida; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso; Santos Júnior, Paulo Villela

2011-10-01

The objective of this study was to compare the antimicrobial effect of mouthwashes containing Calendula officinalis L., Camellia sinensis (L.) Kuntze and 0.12% chlorhexidine digluconate on the adherence of microorganisms to suture materials after extraction of unerupted third molars. Eighteen patients with unerupted maxillary third molars indicated for extraction were selected (n=6 per mouthwash). First, the patients were subjected to extraction of the left tooth and instructed not to use any type of antiseptic solution at the site of surgery (control group). After 15 days, the right tooth was extracted and the patients were instructed to use the Calendula officinalis, Camellia sinensis or chlorhexidine mouthwash during 1 week (experimental group). For each surgery, the sutures were removed on postoperative day 7 and placed in sterile phosphate-buffered saline. Next, serial dilutions were prepared and seeded onto different culture media for the growth of the following microorganisms: blood agar for total microorganism growth; Mitis Salivarius bacitracin sucrose agar for mutans group streptococci; mannitol agar for Staphylococcus spp.; MacConkey agar for enterobacteria and Pseudomonas spp., and Sabouraud dextrose agar containing chloramphenicol for Candida spp. The plates were incubated during 24-48 h at 37ºC for microorganism count (CFU/mL). The three mouthwashes tested reduced the number of microorganisms adhered to the sutures compared to the control group. However, significant differences between the control and experimental groups were only observed for the mouthwash containing 0.12% chlorhexidine digluconate. Calendula officinalis L. and Camellia sinensis (L.) Kuntze presented antimicrobial activity against the adherence of microorganisms to sutures but were not as efficient as chlorhexidine digluconate.

Antimicrobial activity of Calendula officinalis, Camellia sinensis and chlorhexidine against the adherence of microorganisms to sutures after extraction of unerupted third molars

PubMed Central

FARIA, Raquel Lourdes; CARDOSO, Lincoln Marcelo Lourenço; AKISUE, Gokithi; PEREIRA, Cristiane Aparecida; JUNQUEIRA, Juliana Campos; JORGE, Antonio Olavo Cardoso; SANTOS JÚNIOR, Paulo Villela

2011-01-01

Objective The objective of this study was to compare the antimicrobial effect of mouthwashes containing Calendula officinalis L., Camellia sinensis (L.) Kuntze and 0.12% chlorhexidine digluconate on the adherence of microorganisms to suture materials after extraction of unerupted third molars. Material and Methods Eighteen patients with unerupted maxillary third molars indicated for extraction were selected (n=6 per mouthwash). First, the patients were subjected to extraction of the left tooth and instructed not to use any type of antiseptic solution at the site of surgery (control group). After 15 days, the right tooth was extracted and the patients were instructed to use the Calendula officinalis, Camellia sinensis or chlorhexidine mouthwash during 1 week (experimental group). For each surgery, the sutures were removed on postoperative day 7 and placed in sterile phosphate-buffered saline. Next, serial dilutions were prepared and seeded onto different culture media for the growth of the following microorganisms: blood agar for total microorganism growth; Mitis Salivarius bacitracin sucrose agar for mutans group streptococci; mannitol agar for Staphylococcus spp.; MacConkey agar for enterobacteria and Pseudomonas spp., and Sabouraud dextrose agar containing chloramphenicol for Candida spp. The plates were incubated during 24-48 h at 37ºC for microorganism count (CFU/mL). Results The three mouthwashes tested reduced the number of microorganisms adhered to the sutures compared to the control group. However, significant differences between the control and experimental groups were only observed for the mouthwash containing 0.12% chlorhexidine digluconate. Conclusions Calendula officinalis L. and Camellia sinensis (L.) Kuntze presented antimicrobial activity against the adherence of microorganisms to sutures but were not as efficient as chlorhexidine digluconate. PMID:21986652

Effect of antibiotic, Lacto-lase and probiotic addition in chicken feed on protein and fat content of chicken meat

NASA Astrophysics Data System (ADS)

Azhar, Noor Amiza; Abdullah, Aminah

2015-09-01

This research was conducted to investigate the effect of chicken feed additives (antibiotic, Lacto-lase® and probiotic) on protein and fat content of chicken meat. Chicken fed with control diet (corn-soy based diet) served as a control. The treated diets were added with zinc bacitracin (antibiotic), different amount of Lacto-lase® (a mixture of probiotic and enzyme) and probiotic. Chicken were slaughtered at the age of 43-48 days. Each chicken was divided into thigh, breast, drumstick, drumette and wing. Protein content in chicken meat was determined by using macro-Kjeldahl method meanwhile Soxhlet method was used to analyse fat content. The result of the study showed that the protein content of chicken breast was significantly higher (p≤0.05) while thigh had the lowest protein content (p≤0.05). Antibiotic fed chicken was found to have the highest protein content among the treated chickens but there was no significant different with 2g/kg Lacto-lase® fed chicken (p>0.05). All thighs were significantly higher (p≤0.05) in fat content except for drumette of control chicken while breast contained the lowest fat content compared to other chicken parts studied. The control chicken meat contained significantly higher (p≤0.05) amount of fat compared to the other treated chickens. Chicken fed with 2g/kg Lacto-lase® had the lowest (p≤0.05) fat content. The result of this study indicated that the addition of Lacto-lase® as a replacement of antibiotic in chicken feed will not affect the content of protein and fat of chicken meat.

Combined effect of synthetic enterocin CRL35 with cell wall, membrane-acting antibiotics and muranolytic enzymes against Listeria cells.

PubMed

Salvucci, E; Hebert, E M; Sesma, F; Saavedra, L

2010-08-01

To evaluate the inhibition effectiveness of enterocin CRL35 in combination with cell wall, membrane-acting antibiotics and muranolytic enzymes against the foodborne pathogen Listeria. Synthetic enterocin CRL35 alone and in combination with monensin, bacitracin, gramicidin, mutanolysin and lysozyme were used in this study. Minimal inhibitory concentration (MIC) and fractional inhibitory concentration (FIC) index assays were performed using Listeria innocua 7 and Listeria monocytogenes FBUNT as sensitive strains. Antibiotics showed positive interactions with the bacteriocin in both strains tested. On the other hand, when mutanolysin and enterocin CRL35 were added to resting cells in a buffer system, the lytic effect of mutanolysin was enhanced. However, the addition of mutanolysin showed no effect on the growth of L. innocua 7 cells in a culture medium. Moreover, mutanolysin allowed the overgrowth of L. innocua 7 cells to an OD similar to control cells in the presence of inhibitory concentration of enterocin CRL35. In contrast, the combination of lysozyme and enterocin CRL35 resulted in a 50% inhibition of the L. innocua 7 growth. Based on our results, we conclude that the combination of synthetic enterocin CRL35 with some antibiotics is effective against L. innocua 7 and L. monocytogenes FBUNT cells, and more importantly the amount of these agents to be used was considerably reduced. The effectiveness of the combination of synthetic enterocin CRL35 with muramidases seems to depend on complex environments, and more detailed studies need to be performed to elucidate this issue. Enterocin CRL35 represents a promising agent that not only can ensure the quality and safety of food but it can also be combined with several antimicrobial agents important in the medical field.

The occurrence of antibiotics in an urban watershed: From wastewater to drinking water

USGS Publications Warehouse

Watkinson, A.J.; Murby, E.J.; Kolpin, D.W.; Costanzo, S.D.

2009-01-01

The presence of 28 antibiotics in three hospital effluents, five wastewater treatment plants (WWTPs), six rivers and a drinking water storage catchment were investigated within watersheds of South–East Queensland, Australia. All antibiotics were detected at least once, with the exception of the polypeptide bacitracin which was not detected at all. Antibiotics were found in hospital effluent ranging from 0.01–14.5 μg L-1, dominated by the β-lactam, quinolone and sulphonamide groups. Antibiotics were found in WWTP influent up to 64 μg L-1, dominated by the β-lactam, quinolone and sulphonamide groups. Investigated WWTPs were highly effective in removing antibiotics from the water phase, with an average removal rate of greater than 80% for all targeted antibiotics. However, antibiotics were still detected in WWTP effluents in the low ng L-1 range up to a maximum of 3.4 μg L-1, with the macrolide, quinolone and sulphonamide antibiotics most prevalent. Similarly, antibiotics were detected quite frequently in the low ng L-1 range, up to 2 μg L-1 in the surface waters of six investigated rivers including freshwater, estuarine and marine samples. The total investigated antibiotic concentration (TIAC) within the Nerang River was significantly lower (p p < 0.001) was identified between TIACs at surface water sites with WWTP discharge compared to sites with no WWTP discharge, providing further evidence that WWTPs are an important source of antibiotics to streams. Despite the presence of antibiotics in surface waters used for drinking water extraction, no targeted antibiotics were detected in any drinking water samples.

Antibiotic resistance and molecular typing among cockle (Anadara granosa) strains of Vibrio parahaemolyticus by polymerase chain reaction (PCR)-based analysis.

PubMed

Sahilah, A M; Laila, R A S; Sallehuddin, H Mohd; Osman, H; Aminah, A; Ahmad Azuhairi, A

2014-02-01

Genomic DNA of Vibrio parahaemolyticus were characterized by antibiotic resistance, enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) analysis. These isolates originated from 3 distantly locations of Selangor, Negeri Sembilan and Melaka (East coastal areas), Malaysia. A total of 44 (n = 44) of tentatively V. parahaemolyticus were also examined for the presence of toxR, tdh and trh gene. Of 44 isolates, 37 were positive towards toxR gene; while, none were positive to tdh and trh gene. Antibiotic resistance analysis showed the V. parahaemolyticus isolates were highly resistant to bacitracin (92%, 34/37) and penicillin (89%, 33/37) followed by resistance towards ampicillin (68%, 25/37), cefuroxime (38%, 14/37), amikacin (6%, 2/37) and ceftazidime (14%, 5/37). None of the V. parahaemolyticus isolates were resistant towards chloramphenicol, ciprofloxacin, ceftriaxone, enrofloxacin, norfloxacin, streptomycin and vancomycin. Antibiogram patterns exhibited, 9 patterns and phenotypically less heterogenous when compared to PCR-based techniques using ERIC- and RAPD-PCR. The results of the ERIC- and RAPD-PCR were analyzed using GelCompare software. ERIC-PCR with primers ERIC1R and ERIC2 discriminated the V. parahaemolyticus isolates into 6 clusters and 21 single isolates at a similarity level of 80%. While, RAPD-PCR with primer Gen8 discriminated the V. parahaemolyticus isolates into 11 clusters and 10 single isolates and Gen9 into 8 clusters and 16 single isolates at the same similarity level examined. Results in the presence study demonstrated combination of phenotypically and genotypically methods show a wide heterogeneity among cockle isolates of V. parahaemolyticus.

[In vitro release of [5Met]- and [5Leu]-enkephalins from the rat brain crude synaptosomal (P2) fraction: Ca2+-dependency of K+-stimulation and effects of various drugs].

PubMed

Koida, M; Takahashi, M; Takenaga, K

1983-01-01

The rat brain P2 fraction was suspended in Krebs Ringer bicarbonate buffer containing 20 microM bacitracin and incubated at 37 degrees C for 10 min under an atmosphere of 95% O2-5% CO2. Incubation was terminated by centrifugation at 4 degrees C and 10,000 X g for 10 min. The supernatant was designated as the S1 fraction, and from the pellet, the S2 to S4 fractions were collected by repeated suspension, incubation, and centrifugation. The radioimmunoassays of each S fraction revealed the spontaneous release of [5Met]- and [5Leu]-enkephalins at the ratio of 2 to 1. The peptide contents gradually decreased from S1 to S4, but the release tended to become constant in S3 and S4. Thus, the effects of some ions and drugs on the release were compared at the stage of obtaining the S3 fraction. The release of both peptides were significantly stimulated in 50 mM KCl buffer, and the stimulatory effect appears to be dependent on Ca2+ concentration. Veratrine and A23187 were also effective stimulants of the release. On the other hand, neither spontaneous nor K+-stimulated release of enkephalins was affected by morphine (1 microM), naloxone (1 microM), kyotorphin (1 or 10 microM), and Li+ (50 mM). Similar results were obtained with the release of 3H-noradrenaline taken up in vitro by the P2 fraction. The usability of the P2 fraction as an in vitro model for the study of stimulus-coupled release of enkephalins was discussed with some limitations found herein.

Enterotoxin-Encoding Genes in Staphylococcus spp. from Food Handlers in a University Restaurant.

PubMed

da Silva, Sabina Dos Santos Paulino; Cidral, Thiago André; Soares, Maria José dos Santos; de Melo, Maria Celeste Nunes

2015-11-01

Food handlers carrying enterotoxin-producing Staphylococcus are a potential source of food poisoning. The aim of this study was to analyze genes encoding enterotoxins in coagulase-positive Staphylococcus (CoPS) and coagulase-negative Staphylococcus (CoNS) isolated from the anterior nostrils and hands of food handlers at a university restaurant in the city of Natal, Northeast Brazil. Thirty food handlers were screened for the study. The isolates were subjected to Gram staining, a bacitracin sensitivity test, mannitol fermentation, and catalase and coagulase tests. CoNS and CoPS strains were subsequently identified by a Vitek 2 System (BioMerieux, France) and various biochemical tests. Polymerase chain reaction was used to detect genes for enterotoxins A, B, C, D, E, G, H, and I (sea, seb, sec, sed, see, seg, seh, and sei) and a disc-diffusion method was used to determine susceptibility to several classes of antimicrobials. All food handlers presented staphylococci on their hands and/or noses. The study found 58 Staphylococcus spp., of which 20.7% were CoPS and 79.3% were CoNS. S. epidermidis was the most prevalent species. Twenty-nine staphylococci (50%) were positive for one or more enterotoxin genes, and the most prevalent genes were seg and sei, each with a frequency of 29.3%. Indeed, CoNS encoded a high percentage of enterotoxin genes (43.5%). However, S. aureus encoded even more enterotoxin genes (75%). Most isolates showed sensitivity to the antibiotics used for testing, except for penicillin (only 35% sensitive). The results from this study reinforce that coagulase-negative as well as coagulase-positive staphylococci isolated from food handlers are capable of genotypic enterotoxigenicity.

Inhibiting effects of Streptococcus salivarius on competence-stimulating peptide-dependent biofilm formation by Streptococcus mutans.

PubMed

Tamura, S; Yonezawa, H; Motegi, M; Nakao, R; Yoneda, S; Watanabe, H; Yamazaki, T; Senpuku, H

2009-04-01

The effects of Streptococcus salivarius on the competence-stimulating peptide (CSP)-dependent biofilm formation by Streptococcus mutans were investigated. Biofilms were grown on 96-well microtiter plates coated with salivary components in tryptic soy broth without dextrose supplemented with 0.25% sucrose. Biofilm formations were stained using safranin and quantification of stained biofilms was performed by measuring absorbance at 492 nm. S. mutans formed substantial biofilms, whereas biofilms of S. salivarius were formed poorly in the medium conditions used. Furthermore, in combination cultures, S. salivarius strongly inhibited biofilm formation when cultured with S. mutans. This inhibition occurred in the early phase of biofilm formation and was dependent on inactivation of the CSP of S. mutans, which is associated with competence, biofilm formation, and antimicrobial activity of the bacterium, and is induced by expression of the comC gene. Comparisons between the S. mutans clinical strains FSC-3 and FSC-3DeltaglrA in separate dual-species cultures with S. salivarius indicated that the presence of the bacitracin transport ATP-binding protein gene glrA caused susceptibility to inhibition of S. mutans biofilm formation by S. salivarius, and was also associated with the regulation of CSP production by com gene-dependent quorum sensing systems. It is considered that regulation of CSP by glrA in S. mutans and CSP inactivation by S. salivarius are important functions for cell-to-cell communication between biofilm bacteria and oral streptococci such as S. salivarius. Our results provide useful information for understanding the ecosystem of oral streptococcal biofilms, as well as the competition between and coexistence of multiple species in the oral cavity.

Effect of Probiotic Curd on Salivary pH and Streptococcus mutans: A Double Blind Parallel Randomized Controlled Trial.

PubMed

Srivastava, Shivangi; Saha, Sabyasachi; Kumari, Minti; Mohd, Shafaat

2016-02-01

Dairy products like curd seem to be the most natural way to ingest probiotics which can reduce Streptococcus mutans level and also increase salivary pH thereby reducing the dental caries risk. To estimate the role of probiotic curd on salivary pH and Streptococcus mutans count, over a period of 7 days. This double blind parallel randomized clinical trial was conducted at the institution with 60 caries free volunteers belonging to the age group of 20-25 years who were randomly allocated into two groups. Test Group consisted of 30 subjects who consumed 100ml of probiotic curd daily for seven days while an equal numbered Control Group were given 100ml of regular curd for seven days. Saliva samples were assessed at baseline, after ½ hour 1 hour and 7 days of intervention period using pH meter and Mitis Salivarius Bacitracin agar to estimate salivary pH and S. mutans count. Data was statistically analysed using Paired and Unpaired t-test. The study revealed a reduction in salivary pH after ½ hour and 1 hour in both the groups. However after 7 days, normal curd showed a statistically significant (p< 0.05) reduction in salivary pH while probiotic curd showed a statistically significant (p< 0.05) increase in salivary pH. Similarly with regard to S. mutans colony counts probiotic curd showed statistically significant reduction (p< 0.05) as compared to normal curd. Short-term consumption of probiotic curds showed marked salivary pH elevation and reduction of salivary S. mutans counts and thus can be exploited for the prevention of enamel demineralization as a long-term remedy keeping in mind its cost effectiveness.

Catalogue of antibiotic resistome and host-tracking in drinking water deciphered by a large scale survey.

PubMed

Ma, Liping; Li, Bing; Jiang, Xiao-Tao; Wang, Yu-Lin; Xia, Yu; Li, An-Dong; Zhang, Tong

2017-11-28

Excesses of antibiotic resistance genes (ARGs), which are regarded as emerging environmental pollutants, have been observed in various environments. The incidence of ARGs in drinking water causes potential risks to human health and receives more attention from the public. However, ARGs harbored in drinking water remain largely unexplored. In this study, we aimed at establishing an antibiotic resistome catalogue in drinking water samples from a wide range of regions and to explore the potential hosts of ARGs. A catalogue of antibiotic resistome in drinking water was established, and the host-tracking of ARGs was conducted through a large-scale survey using metagenomic approach. The drinking water samples were collected at the point of use in 25 cities in mainland China, Hong Kong, Macau, Taiwan, South Africa, Singapore and the USA. In total, 181 ARG subtypes belonging to 16 ARG types were detected with an abundance range of 2.8 × 10 -2 to 4.2 × 10 -1 copies of ARG per cell. The highest abundance was found in northern China (Henan Province). Bacitracin, multidrug, aminoglycoside, sulfonamide, and beta-lactam resistance genes were dominant in drinking water. Of the drinking water samples tested, 84% had a higher ARG abundance than typical environmental ecosystems of sediment and soil. Metagenomic assembly-based host-tracking analysis identified Acidovorax, Acinetobacter, Aeromonas, Methylobacterium, Methyloversatilis, Mycobacterium, Polaromonas, and Pseudomonas as the hosts of ARGs. Moreover, potential horizontal transfer of ARGs in drinking water systems was proposed by network and Procrustes analyses. The antibiotic resistome catalogue compiled using a large-scale survey provides a useful reference for future studies on the global surveillance and risk management of ARGs in drinking water. .

Effects of the bradykinin antagonist B4310 on smooth muscles and blood pressure in the rat, and its enzymatic degradation.

PubMed Central

Griesbacher, T.; Lembeck, F.; Saria, A.

1989-01-01

1. Six competitive bradykinin (Bk) antagonists were tested for their agonistic properties on the rat uterus. Five of these peptides showed agonistic effects only at concentrations at least two orders of magnitude higher than those of bradykinin. 2. The antagonistic potency of Lys-Lys-3-Hyp-5,8-Thi-7-DPhe-Bk (B4310) in the rat uterus (pA2 = 7.24) and in the rat duodenum (pA2 = 7.31) was very similar to that determined in an earlier study for the antagonism of the bradykinin-induced stimulation of the trigeminal nerve in the rabbit iris sphincter muscle preparation (pA2 = 7.59). 3. The fall in mean arterial blood pressure induced by i.a. injections of bradykinin was greatly reduced during an i.a. infusion of B4310, but not 10 min thereafter, which indicates a rapid inactivation of B4310 in vivo. Bacitracin possibly interferes with the enzymatic cleavage of B4310 but seems to have no effect on the degradation of bradykinin. 4. An i.a. infusion of captopril greatly enhanced the potency of bradykinin in inducing a fall in arterial blood pressure, confirming the important role of angiotensin converting enzyme in the cleavage of bradykinin. However, the design of this experiment did not allow conclusions about the effect of captopril on the degradation of B4310. 5. B4310 incubated with rat lung tissue disappeared from the incubation medium within a few minutes, i.e. as fast as bradykinin, which explains its short duration of action in vivo. Captopril partially inhibited the cleavage of both bradykinin and B4310.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2655805

Effect of activated protein C in second intention healing of equine distal limb wounds: a preliminary study.

PubMed

Bischofberger, A S; Tsang, A S; Horadagoda, N; Dart, C M; Perkins, N R; Jeffcott, L B; Jackson, C J; Dart, A J

2015-10-01

To investigate the effect of activated protein C (APC) on second intention healing of distal limb wounds in horses. In this experimental study of eight Standardbred geldings, six full-thickness skin wounds (2 × 1.5 cm) were created on one metacarpus (biopsy limb) and five similar wounds were created on the contralateral metacarpus (photographed limb). Three wounds on the biopsy limb were treated topically with 190 µg APC on days 1, 3, 6 and 9, while the remaining three wounds were untreated (control). One treated and one control wound were biopsied on days 4, 7 and 11 for histopathology. Wounds on the photographed limb were treated with either 66% Manuka honey gel, a commercial antibiotic ointment (bacitracin-neomycin-polymixin B ointment; BNP) or petrolatum daily throughout healing, treated on days 1,3,6 and 9 with 190 µg APC or left untreated. These wounds were digitally photographed and the wound area measured on day 1, then weekly until day 49. Overall time to healing was recorded. There was no effect of APC on wound size, the rate of healing or the overall time to heal. However, compared with control wounds, histological scoring demonstrated enhanced epithelialisation (day 4) and angiogenesis (day 11). Wound healing variables for wounds treated with APC, Manuka honey gel and control wounds were not different and the variables for wounds treated with BNP and petrolatum demonstrated delayed healing. The improvements in histological scores in APC-treated wounds suggest further study into the effect of APC on second intention wound healing in horses is warranted. © 2015 Australian Veterinary Association.

The Purine-Utilizing Bacterium Clostridium acidurici 9a: A Genome-Guided Metabolic Reconsideration

PubMed Central

Hartwich, Katrin; Poehlein, Anja; Daniel, Rolf

2012-01-01

Clostridium acidurici is an anaerobic, homoacetogenic bacterium, which is able to use purines such as uric acid as sole carbon, nitrogen, and energy source. Together with the two other known purinolytic clostridia C. cylindrosporum and C. purinilyticum, C. acidurici serves as a model organism for investigation of purine fermentation. Here, we present the first complete sequence and analysis of a genome derived from a purinolytic Clostridium. The genome of C. acidurici 9a consists of one chromosome (3,105,335 bp) and one small circular plasmid (2,913 bp). The lack of candidate genes encoding glycine reductase indicates that C. acidurici 9a uses the energetically less favorable glycine-serine-pyruvate pathway for glycine degradation. In accordance with the specialized lifestyle and the corresponding narrow substrate spectrum of C. acidurici 9a, the number of genes involved in carbohydrate transport and metabolism is significantly lower than in other clostridia such as C. acetobutylicum, C. saccharolyticum, and C. beijerinckii. The only amino acid that can be degraded by C. acidurici is glycine but growth on glycine only occurs in the presence of a fermentable purine. Nevertheless, the addition of glycine resulted in increased transcription levels of genes encoding enzymes involved in the glycine-serine-pyruvate pathway such as serine hydroxymethyltransferase and acetate kinase, whereas the transcription levels of formate dehydrogenase-encoding genes decreased. Sugars could not be utilized by C. acidurici but the full genetic repertoire for glycolysis was detected. In addition, genes encoding enzymes that mediate resistance against several antimicrobials and metals were identified. High resistance of C. acidurici towards bacitracin, acriflavine and azaleucine was experimentally confirmed. PMID:23240052

The purine-utilizing bacterium Clostridium acidurici 9a: a genome-guided metabolic reconsideration.

PubMed

Hartwich, Katrin; Poehlein, Anja; Daniel, Rolf

2012-01-01

Clostridium acidurici is an anaerobic, homoacetogenic bacterium, which is able to use purines such as uric acid as sole carbon, nitrogen, and energy source. Together with the two other known purinolytic clostridia C. cylindrosporum and C. purinilyticum, C. acidurici serves as a model organism for investigation of purine fermentation. Here, we present the first complete sequence and analysis of a genome derived from a purinolytic Clostridium. The genome of C. acidurici 9a consists of one chromosome (3,105,335 bp) and one small circular plasmid (2,913 bp). The lack of candidate genes encoding glycine reductase indicates that C. acidurici 9a uses the energetically less favorable glycine-serine-pyruvate pathway for glycine degradation. In accordance with the specialized lifestyle and the corresponding narrow substrate spectrum of C. acidurici 9a, the number of genes involved in carbohydrate transport and metabolism is significantly lower than in other clostridia such as C. acetobutylicum, C. saccharolyticum, and C. beijerinckii. The only amino acid that can be degraded by C. acidurici is glycine but growth on glycine only occurs in the presence of a fermentable purine. Nevertheless, the addition of glycine resulted in increased transcription levels of genes encoding enzymes involved in the glycine-serine-pyruvate pathway such as serine hydroxymethyltransferase and acetate kinase, whereas the transcription levels of formate dehydrogenase-encoding genes decreased. Sugars could not be utilized by C. acidurici but the full genetic repertoire for glycolysis was detected. In addition, genes encoding enzymes that mediate resistance against several antimicrobials and metals were identified. High resistance of C. acidurici towards bacitracin, acriflavine and azaleucine was experimentally confirmed.

Effect of an alcoholic diet on dental caries and on Streptococcus of the mutans group. Study in rats.

PubMed

Kantorski, Karla Zanini; de Souza, Daniela Martins; Yujra, Verônica Quispe; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso; da Rocha, Rosilene Fernandes

2007-01-01

The objective of this study was to evaluate the effects of an alcohol diet on Streptococcus of the mutans group and on dental caries in the oral cavity of rats. Forty animals were divided into 3 groups according to the following liquid diets: 20% ethanol solution (Alcohol Group, AG), 27% sucrose solution (Isocaloric Group, IG), and water (Control Group, CG). After 56 days, samples were collected and plated on Mitis Salivarius Bacitracin agar to assess the number of colony forming units (CFU/mL) of Streptococcus of the mutans group. The animals were sacrificed and the jaws were removed in order to assess the occurrence of dental caries on the smooth and occlusal surfaces using stereomicroscopy. The data were submitted to ANOVA and Tukey test. The average numbers of CFU/mL (10(3)) were: 8.17 (AG), 9.78 (IG), and 5.63 (CG). There was no significant difference among the groups for the occurrence of occlusal caries. Regarding smooth surface caries, in the upper jaw, the caries number in the IG (1.58) was similar to that in the AG (2.06) and in the CG (1.14), and the number of caries in the AG was higher than in the CG; in the lower jaw there was significant difference among the 3 groups: AG (1.14), IG (2.00) and CG (0.43). The diets with the alcohol and sucrose solutions presented a tendency of increasing the colonization by Streptococcus of the mutans group and of increasing the occurrence of smooth surface dental caries in rat molars when compared to the control diet.

Reduced salivary flow and colonization by mutans streptococci in children with Down syndrome

PubMed Central

Areias, Cristina; Sampaio-Maia, Benedita; de Lurdes Pereira, Maria; Azevedo, Álvaro; Melo, Paulo; Andrade, Casimiro; Scully, Crispian

2012-01-01

OBJECTIVES: Although individuals with Down syndrome have considerable oral disease, the prevalence of dental caries in this group is low. The present study aimed to compare known risk factors for dental caries development in children with Down syndrome and a matched population (siblings). In both populations, the number of acidogenic microorganisms, such as mutans streptococci, lactobacilli and Candida species, and the paraffin-stimulated pH, flow rate and IgA concentration in whole saliva were evaluated and compared. METHOD: Saliva was collected, and the caries index was evaluated in 45 sibling pairs aged between 6 and 18 years old. The salivary IgA concentration was determined by immunoturbidimetry. Salivary mutans streptococci, lactobacilli and Candida species were quantified on mitis salivarius agar containing bacitracin and 20% sucrose, rogosa agar supplemented with glacial acetic acid and sabouraud agar supplemented with chloramphenicol, respectively. RESULTS: Down syndrome children had a higher caries-free rate (p<0.05) and lower salivary mutans streptococci counts (p<0.03) compared to their siblings. Similar numbers of lactobacilli and Candida species were found in both groups. Salivary flow rates were 36% lower in Down syndrome children compared to their siblings (p<0.05). The salivary pH did not differ between Down syndrome children and controls. The Down syndrome children had an IgA secretion rate 29% lower than that of their siblings, but this difference was not statistically significant. CONCLUSIONS: In conclusion, the lower number of mutans streptococci in the saliva may be one of the factors contributing to the lower caries rate observed in Down syndrome children, despite evidence of hyposalivation. PMID:23018295

Effect of peptidases on the ability of exogenous and endogenous neurokinins to produce neurokinin 1 receptor internalization in the rat spinal cord

PubMed Central

Marvizón, Juan Carlos G; Wang, Xueren; Lao, Li-Jun; Song, Bingbing

2003-01-01

The ability of peptidases to restrict neurokinin 1 receptor (NK1R) activation by exogenously applied or endogenously released neurokinins was investigated by measuring NK1R internalization in rat spinal cord slices. Concentration–response curves for substance P and neurokinin A were obtained in the presence and absence of 10 μM thiorphan, an inhibitor of neutral endopeptidase (EC 3.4.24.11), plus 10 μM captopril, an inhibitor of dipeptidyl carboxypeptidase (EC 3.4.15.1). These inhibitors significantly decreased the EC50 of substance P to produce NK1R internalization from 32 to 9 nM, and the EC50 of neurokinin A from 170 to 60 nM. Substance P was significantly more potent than neurokinin A, both with and without these peptidase inhibitors. In the presence of peptidase inhibitors, neurokinin B was 10 times less potent than neurokinin A and 64 times less potent than substance P (EC50=573 nM). Several aminopeptidase inhibitors (actinonin, amastatin, bacitracin, bestatin and puromycin) failed to further increase the effect of thiorphan plus captopril on the NK1R internalization produced by 10 nM substance P. Electrical stimulation of the dorsal root produced NK1R internalization by releasing endogenous neurokinins. Thiorphan plus captopril increased NK1R internalization produced by 1 Hz stimulation, but not by 30 Hz stimulation. Therefore, NEN and DCP restrict NK1R activation by endogenous neurokinins when they are gradually released by low-frequency firing of primary afferents, but become saturated or inhibited when primary afferents fire at a high frequency. PMID:14623771

Alternative Growth Promoters Modulate Broiler Gut Microbiome and Enhance Body Weight Gain

PubMed Central

Salaheen, Serajus; Kim, Seon-Woo; Haley, Bradd J.; Van Kessel, Jo Ann S.; Biswas, Debabrata

2017-01-01

Antibiotic growth promoters (AGPs) are frequently used to enhance weight-gain in poultry production. However, there has been increasing concern over the impact of AGP on the emergence of antibiotic resistance in zoonotic bacterial pathogens in the microbial community of the poultry gut. In this study, we adopted mass-spectrophotometric, phylogenetic, and shotgun-metagenomic approaches to evaluate bioactive phenolic extracts (BPE) from blueberry (Vaccinium corymbosum) and blackberry (Rubus fruticosus) pomaces as AGP alternatives in broilers. We conducted two trials with 100 Cobb-500 broiler chicks (in each trial) in four equal groups that were provided water with no supplementation, supplemented with AGP (tylosin, neomycin sulfate, bacitracin, erythromycin, and oxytetracycline), or supplemented with 0.1 g Gallic acid equivalent (GAE)/L or 1.0 g GAE/L (during the last 72 h before euthanasia) of BPE for 6 weeks. When compared with the control group (water only), the chickens supplemented with AGP and 0.1 g GAE/L of BPE gained 9.5 and 5.8% more body weight, respectively. The microbiomes of both the AGP- and BPE-treated chickens had higher Firmicutes to Bacteroidetes ratios. AGP supplementation appeared to be associated with higher relative abundance of bacteriophages and unique cecal resistomes compared with BPE supplementation or control. Functional characterization of cecal microbiomes revealed significant animal-to-animal variation in the relative abundance of genes involved in energy and carbohydrate metabolism. These findings established a baseline upon which mechanisms of plant-based performance enhancers in regulation of animal growth can be investigated. In addition, the data will aid in designing alternate strategies to improve animal growth performance and consequently production. PMID:29123512

Role of annexin A5 in cisplatin-induced toxicity in renal cells: molecular mechanism of apoptosis.

PubMed

Jeong, Jin-Joo; Park, Nahee; Kwon, Yeo-Jung; Ye, Dong-Jin; Moon, Aree; Chun, Young-Jin

2014-01-24

Annexin A5 belongs to a large family of calcium-binding and phospholipid-binding proteins and may act as an endogenous regulator of various pathophysiological processes. There is increasing evidence that annexin A5 is related to cytotoxicity, but the precise function of this protein has yet to be elucidated. In this study, we aimed to verify the function of annexin A5 in the apoptosis of renal epithelial cells. Real-time PCR and Western blot analysis, together with immunofluorescence analysis, showed that the expression of annexin A5 significantly increased in the presence of cisplatin in both human and rat renal epithelial cells. With regard to the mechanism of cisplatin-induced apoptosis, apoptosis-inducing factor (AIF) release into the cytosol was observed, and the underlying mechanism was identified as voltage-dependent anion channel (VDAC) oligomerization. Mitochondrial membrane potential (Δψm) was found to be greatly disrupted in cisplatin-treated cells. Moreover, cisplatin strongly induced translocation of annexin A5 into mitochondria. To understand the functional significance of annexin A5 in renal cell death, we used a siRNA-mediated approach to knock down annexin A5. Annexin A5 depletion by siRNA led to decreased annexin A5 translocation into mitochondria and significantly reduced VDAC oligomerization and AIF release. Annexin A5 siRNA also increased cell viability compared with the control. Moreover, expression of annexin A5 was induced by other nephrotoxicants such as CdCl2 and bacitracin. Taken together, our data suggest that annexin A5 may play a crucial role in cisplatin-induced toxicity by mediating the mitochondrial apoptotic pathway via the induction and oligomerization of VDAC.

Role of PknB kinase in antibiotic resistance and virulence in community-acquired methicillin-resistant Staphylococcus aureus strain USA300.

PubMed

Tamber, Sandeep; Schwartzman, Joseph; Cheung, Ambrose L

2010-08-01

The regulation of cellular processes by eukaryote-like serine/threonine kinases is widespread in bacteria. In the last 2 years, several studies have examined the role of serine/threonine kinases in Staphylococcus aureus on cell wall metabolism, autolysis, and virulence, mostly in S. aureus laboratory isolates in the 8325-4 lineage. In this study, we showed that the pknB gene (also called stk1) of methicillin-resistant S. aureus (MRSA) strain COL and the community-acquired MRSA (CA-MRSA) strain USA300 is involved in cell wall metabolism, with the pknB mutant exhibiting enhanced sensitivity to beta-lactam antibiotics but not to other classes of antibiotics, including aminoglycosides, ciprofloxacin, bactrim, and other types of cell wall-active agents (e.g., vancomycin and bacitracin). Additionally, the pknB mutant of USA300 was found to be more resistant to Triton X-100-induced autolysis and also to lysis by lysostaphin. We also showed that pknB is a positive regulator of sigB activity, resulting in compromise in its response to heat and oxidative stresses. In association with reduced sigB activity, the expression levels of RNAII and RNAIII of agr and the downstream effector hla are upregulated while spa expression is downmodulated in the pknB mutant compared to the level in the parent. Consistent with an enhanced agr response in vitro, virulence studies of the pknB mutant of USA300 in a murine cutaneous model of infection showed that the mutant was more virulent than the parental strain. Collectively, our results have linked the pknB gene in CA-MRSA to antibiotic resistance, sigB activity, and virulence and have highlighted important differences in pknB phenotypes (virulence and sigB activity) between laboratory isolates and the prototypic CA-MRSA strain USA300.

Antibiotic Effects on Methicillin-Resistant Staphylococcus aureus Cytoplasmic Peptidoglycan Intermediate Levels and Evidence for Potential Metabolite Level Regulatory Loops.

PubMed

Vemula, Harika; Ayon, Navid J; Burton, Alloch; Gutheil, William G

2017-06-01

Cytoplasmic peptidoglycan (PG) precursor levels were determined in methicillin-resistant Staphylococcus aureus (MRSA) after exposure to several cell wall-targeting antibiotics. Three experiments were performed: (i) exposure to 4× MIC levels (acute); (ii) exposure to sub-MIC levels (subacute); (iii) a time course experiment of the effect of vancomycin. In acute exposure experiments, fosfomycin increased UDP-GlcNAc, as expected, and resulted in substantially lower levels of total UDP-linked metabolite accumulation relative to other pathway inhibitors, indicating reduced entry into this pathway. Upstream inhibitors (fosfomycin, d-cycloserine, or d-boroalanine) reduced UDP-MurNAc-pentapeptide levels by more than fourfold. Alanine branch inhibitors (d-cycloserine and d-boroalanine) reduced d-Ala-d-Ala levels only modestly (up to 4-fold) but increased UDP-MurNAc-tripeptide levels up to 3,000-fold. Downstream pathway inhibitors (vancomycin, bacitracin, moenomycin, and oxacillin) increased UDP-MurNAc-pentapeptide levels up to 350-fold and UDP-MurNAc-l-Ala levels up to 80-fold, suggesting reduced MurD activity by downstream inhibitor action. Sub-MIC exposures demonstrated effects even at 1/8× MIC which strongly paralleled acute exposure changes. Time course data demonstrated that UDP-linked intermediate levels respond rapidly to vancomycin exposure, with several intermediates increasing three- to sixfold within minutes. UDP-linked intermediate level changes were also multiphasic, with some increasing, some decreasing, and some increasing and then decreasing. The total (summed) UDP-linked intermediate pool increased by 1,475 μM/min during the first 10 min after vancomycin exposure, providing a revised estimate of flux in this pathway during logarithmic growth. These observations outline the complexity of PG precursor response to antibiotic exposure in MRSA and indicate likely sites of regulation (entry and MurD). Copyright © 2017 American Society for Microbiology.

Effect of Green Coffee Bean Extract on Streptococcus mutans Count: A Randomised Control Trial

PubMed Central

Kaushik, Mamta; Roshni, Roshni; Reddy, Pallavi; Mehra, Neha; Jain, Vallari; Rana, Ritu

2017-01-01

Introduction Mouth rinses have been popularly used as a supplementary oral hygiene aid. A lot of commercially available mouth rinses possess few adverse effects, which has necessitated the search for alternative and herbal mouth rinses. Aim The aim of the study was to assess the effect of rinsing with green coffee bean extract in comparison with chlorhexidine mouthwash and sterile water on salivary Streptococcus mutans count. Materials and Methods A randomized parallel controlled clinical trial was planned and 45 subjects aged between 18-22 years were selected. The subjects were divided into three groups (n=15 in each group): Group A: Study group: 2% Green coffee bean extract, Group B: Positive control: 0.2% Chlorhexidine (CHX), Group C: Negative control: Sterile water. Group A subjects rinsed mouth with 5 ml of 2% Green coffee bean extract for one minute. Group B subjects rinsed mouth with 5 ml 0.2% CHX mouthwash for one minute. Group C subjects rinsed mouth with 5 ml of Sterile water for one minute twice daily for two weeks. Baseline samples (Pre rinse) were collected on day 1 and post rinsing saliva samples were collected after 14 days. The samples were cultured using Mitis Salivarius Agar enriched with Bacitracin and colonies were counted using a hand held digital colony counter. The statistical analysis was done using paired t-test, One-way variance ANOVA and Post-Hoc tests. Results The Green coffee bean extract group showed a statistical significant reduction in Streptococcus mutans colony count before and after intervention which was comparable with CHX group. Conclusion Green coffee bean extract as a mouthwash can be explored as a safe and effective alternative to CHX mouthwash. PMID:28658911

Specific uptake, dissociation, and degradation of /sup 125/I-labeled insulin in isolated turtle (Chrysemys dorbigni) thyroid glands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marques, M.; da Silva, R.S.; Turyn, D.

1985-11-01

Thyroid glands from turtles (Chrysemys dorbigni) pretreated with potassium iodide were incubated with /sup 125/I-insulin in the presence or absence of unlabeled insulin, in order to study its specific uptake. At 24 degrees, the specific uptake reached a plateau at 180 min of incubation. The dose of bovine insulin that inhibited 50% of the /sup 125/I-insulin uptake was 2 micrograms/ml of incubation medium. Most of the radioactive material (71%) extracted from the gland, after 30 min incubation with /sup 125/I-insulin, eluted in the same position as labeled insulin on Sephadex G-50. Only 24% eluted in the salt position. After 240more » min incubation, increased amount of radioactivity appeared in the Na/sup 125/I position. When bovine insulin was added together with the labeled hormone, a substantial reduction of radioactivity was observed in the insulin and Na/sup 125/I elution positions. Dissociation studies were performed at 6 degrees in glands preincubated with /sup 125/I-insulin either at 24 or 6 degrees. The percentage of trichloroacetic acid (TCA)-soluble radioactive material in the dissociation medium increased with incubation time at both temperatures. However, the degradation activity was lower at 6 than at 24 degrees. The addition of bovine insulin to the incubation buffer containing /sup 125/I-insulin reduced the radioactive degradation products in the dissociated medium. Chloroquine or bacitracin inhibited the degradation activity. Incubation of thyroid glands with /sup 125/I-hGH or /sup 125/I-BSA showed values of uptake, dissociation, and degradation similar to those experiments in which an excess of bovine insulin was added together with the labeled hormone. Thus, by multiple criteria, such as specific uptake, dissociation, and degradation, the presence of insulin-binding sites in the turtle thyroid gland may be suggested.« less

Effect of yeast-derived products and distillers dried grains with solubles (DDGS) on growth performance and local innate immune response of broiler chickens challenged with Clostridium perfringens.

PubMed

Alizadeh, M; Rogiewicz, A; McMillan, E; Rodriguez-Lecompte, J C; Patterson, R; Slominski, B A

2016-06-01

This study evaluated the effect of yeast-derived products on growth performance, gut lesion score, intestinal population of Clostridium perfringens, and local innate immunity of broiler chickens challenged with C. perfringens. One-day-old broiler chickens were randomly assigned to eight dietary treatments providing six replicate pens of 55 birds each per treatment. Dietary treatments consisted of Control diets without and with C. perfringens challenge, and diets containing bacitracin methylene disalicylate (BMD, 55 g/tonne), nucleotides (150 g/tonne), yeast cell wall (YCW, 300 g/tonne), and a commercial product Maxi-Gen Plus (1 kg/tonne) fed to chickens challenged with C. perfringens. Diets containing 10% distillers dried grains with solubles without and with C. perfringens challenge were also used. Birds were orally challenged with C. perfringens (10(8) colony-forming units (cfu)/bird) on day 14. On day 21, intestinal samples were collected for gene expression analysis. Pathogen challenge significantly (P < 0.05) impaired feed intake, body weight gain, and feed conversion ratio (FCR) shortly after the challenge (14-21 days). Increased C. perfringens counts and intestinal lesion scores were observed for challenged birds except the BMD-containing diet. Over the entire trial (1-35 days), no difference in growth performance was observed except the BMD diet which improved FCR over the Control, challenged group. Birds receiving nucleotides showed increased expression of toll-like receptors and cytokines interleukin (IL)-4 and IL-18 compared to the Control, challenged group. Expression of macrophage mannose receptor and IL-18 was upregulated in birds receiving YCW. Increased expression of cytokines and receptors involved in innate immunity in broilers receiving nucleotides and YCW suggests the immunomodulatory properties of these products under pathogen challenge conditions.

Disturbance of the gut microbiota in early-life selectively affects visceral pain in adulthood without impacting cognitive or anxiety-related behaviors in male rats.

PubMed

O'Mahony, S M; Felice, V D; Nally, K; Savignac, H M; Claesson, M J; Scully, P; Woznicki, J; Hyland, N P; Shanahan, F; Quigley, E M; Marchesi, J R; O'Toole, P W; Dinan, T G; Cryan, J F

2014-09-26

Disruption of bacterial colonization during the early postnatal period is increasingly being linked to adverse health outcomes. Indeed, there is a growing appreciation that the gut microbiota plays a role in neurodevelopment. However, there is a paucity of information on the consequences of early-life manipulations of the gut microbiota on behavior. To this end we administered an antibiotic (vancomycin) from postnatal days 4-13 to male rat pups and assessed behavioral and physiological measures across all aspects of the brain-gut axis. In addition, we sought to confirm and expand the effects of early-life antibiotic treatment using a different antibiotic strategy (a cocktail of pimaricin, bacitracin, neomycin; orally) during the same time period in both female and male rat pups. Vancomycin significantly altered the microbiota, which was restored to control levels by 8 weeks of age. Notably, vancomycin-treated animals displayed visceral hypersensitivity in adulthood without any significant effect on anxiety responses as assessed in the elevated plus maze or open field tests. Moreover, cognitive performance in the Morris water maze was not affected by early-life dysbiosis. Immune and stress-related physiological responses were equally unaffected. The early-life antibiotic-induced visceral hypersensitivity was also observed in male rats given the antibiotic cocktail. Both treatments did not alter visceral pain perception in female rats. Changes in visceral pain perception in males were paralleled by distinct decreases in the transient receptor potential cation channel subfamily V member 1, the α-2A adrenergic receptor and cholecystokinin B receptor. In conclusion, a temporary disruption of the gut microbiota in early-life results in very specific and long-lasting changes in visceral sensitivity in male rats, a hallmark of stress-related functional disorders of the brain-gut axis such as irritable bowel disorder. Copyright © 2014 IBRO. Published by Elsevier Ltd. All

Effect of dietary inclusion of spray-dried porcine plasma on performance, some physiological and immunological response of broiler chickens challenged with Salmonella sofia.

PubMed

Beski, S S M; Swick, R A; Iji, P A

2016-10-01

This study was conducted to investigate the effect of spray-dried porcine plasma (SDPP) in broiler chickens under Salmonella sofia disease challenge. The experiment comprised five starter diets: positive control (no supplement), diet supplemented with in-feed antibiotics (IFA; salinomycin 0.05% + zinc bacitracin 0.033%) and diets supplemented with SDPP at 10 or 20 g/kg diet. All four of these groups were challenged with S. sofia, while a fifth group was unchallenged and used as the negative control. The experimental diets were fed to 14 days; then, the birds were switched to commercial-type grower and finisher diets. Oral inoculation of the challenged groups with S. sofia occurred on day 8, 10 and 12. Body weight was significantly higher in the birds fed diets containing IFA and SDPP than in the challenged control group, but it was only significant in starter and grower phases. In general, there was an improvement in the weights of the immune-related organs, but it was only significant for the weight of the bursa of SDPP-fed birds at 13 days. At day 13, blood potassium content was lower and the concentrations of IgG and IgM tended to be lower in the birds fed on low-SDPP starter diets than those of the other groups. There were significant differences in the concentration of lactic acid in the ileum and acetic acid, formic acid, butyric acid and propionic acid in the caeca. Inclusion of SDPP to the starter diets of broiler chicks had positive effects on broiler performance, immunity and gut health during exposure to highly pathogenic conditions. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

The occurrence of antibiotics in an urban watershed: from wastewater to drinking water.

PubMed

Watkinson, A J; Murby, E J; Kolpin, D W; Costanzo, S D

2009-04-01

The presence of 28 antibiotics in three hospital effluents, five wastewater treatment plants (WWTPs), six rivers and a drinking water storage catchment were investigated within watersheds of South-East Queensland, Australia. All antibiotics were detected at least once, with the exception of the polypeptide bacitracin which was not detected at all. Antibiotics were found in hospital effluent ranging from 0.01-14.5 microg L(-1), dominated by the beta-lactam, quinolone and sulphonamide groups. Antibiotics were found in WWTP influent up to 64 microg L(-1), dominated by the beta-lactam, quinolone and sulphonamide groups. Investigated WWTPs were highly effective in removing antibiotics from the water phase, with an average removal rate of greater than 80% for all targeted antibiotics. However, antibiotics were still detected in WWTP effluents in the low ng L(-1) range up to a maximum of 3.4 microg L(-1), with the macrolide, quinolone and sulphonamide antibiotics most prevalent. Similarly, antibiotics were detected quite frequently in the low ng L(-1) range, up to 2 microg L(-1) in the surface waters of six investigated rivers including freshwater, estuarine and marine samples. The total investigated antibiotic concentration (TIAC) within the Nerang River was significantly lower (p<0.05) than all other rivers sampled. The absence of WWTP discharge to this river is a likely explanation for the significantly lower TIAC and suggests that WWTP discharges are a dominant source of antibiotics to investigated surface waters. A significant difference (p<0.001) was identified between TIACs at surface water sites with WWTP discharge compared to sites with no WWTP discharge, providing further evidence that WWTPs are an important source of antibiotics to streams. Despite the presence of antibiotics in surface waters used for drinking water extraction, no targeted antibiotics were detected in any drinking water samples.

Phenotypic and Molecular Characteristics of Streptococcus agalactiae Isolates Recovered from Milk of Dairy Cows in Brazil

PubMed Central

Duarte, Rafael S.; Miranda, Otávio P.; Bellei, Bruna C.; Brito, Maria Aparecida V. P.; Teixeira, Lúcia M.

2004-01-01

Information on the characteristics of Streptococcus agalactiae obtained from bovine sources in Brazil is still very limited. The aim of this study was to assess the phenotypic and genotypic diversity among S. agalactiae isolates from milk of dairy cows presenting clinical or subclinical mastitis in the southeast region of Brazil. Phenotypic characterization was based on physiological and serological tests. Antimicrobial susceptibility tests were carried out by the disk method. Genetic diversity was evaluated by using random amplified polymorphic DNA-PCR (RAPD-PCR) (by using the primer 1254) and pulsed-field gel electrophoresis (PFGE) (by using SmaI as the restriction enzyme) and by PCRs for detection of genes associated with resistance to erythromycin and tetracycline as well as PCRs for detection of genes coding for cell surface-associated proteins. According to the results of physiologic tests, 45 (52.9%) isolates showed beta-hemolysis and 44 (51.7%) were susceptible to bacitracin. Fourteen different biotypes were detected. The two most frequent biotypes comprised strains that were non-beta-hemolytic; fermented galactose, lactose, and salicin; produced protease; and were negative for DNase production. Serotype III was predominant (66 isolates [77.6%]), followed by serotypes II, Ia, Ib, and VI. Resistance to tetracycline and erythromycin was found in 38 (44.7%) and 9 (10.5%) isolates, respectively, with tet(O) (31.7%) and erm(B) (100%) being the most frequently occurring resistance genes. Three genes coding for surface proteins, bca, lmb, and scpB, were detected in 55 (64.7%), 7 (8.2%), and 43 (50.5%) isolates, respectively. In most cases, isolates from animals in the same herd presented closely related genetic profiles (determined by either RAPD-PCR or PFGE), which were distinct from those of isolates from different herds. PMID:15365014

PREVALENCE, BIOCHEMICAL CHARACTERISTICS, AND ANTIBIOTIC SUSCEPTIBILITY OF AEROMONADS, VIBRIOS, AND PLESIOMONADS ISOLATED FROM DIFFERENT SOURCES AT A ZOO.

PubMed

Kim, Kyoo-Tae; Lee, Seung-Hun; Kwak, Dongmi

2015-06-01

Aeromonas spp., Vibrio parahaemolyticus , and Plesiomonas shigelloides are commonly implicated in foodborne and waterborne diarrheal illnesses of humans and other animals. The present study assessed the prevalence, biochemical characteristics, and antibiotic susceptibility of Aeromonas spp., V. parahaemolyticus , and P. shigelloides by analyzing samples from 729 sources at a zoo, including animal feces (n=607), watering facilities (n=104), and pond water samples (n=18). Of the 729 samples collected, 40 (5.5%) contained one of these four species of bacteria: A. hydrophila (n=16; 2.2%), A. sobria (n=12; 1.6%), V. parahaemolyticus (n=10; 1.4%), and P. shigelloides (n=2; 0.3%). The 16 isolates of A. hydrophila came from three fecal samples, eight watering facilities, and five pond water samples. The 12 isolates of A. sobria came from four fecal samples, three watering facilities, and five pond water samples. The 10 isolates of V. parahaemolyticus came from one fecal sample and nine watering facilities. The two isolates of P. shigelloides came from one watering facility and one pond water sample. Of the 40 isolates, 16 (40.0%), 21 (52.5%), and three (7.5%) originated from mammals, birds, and reptiles, respectively. All isolates tested positive for NO3, tryptophan, p-nitrophenyl-β-D-galactopyranoside, glucose assimilation, N-acetyl-glucosamine, maltose, gluconate, malate, and oxidase. Aeromonas spp. and V. parahaemolyticus exhibited similar biochemical characteristics, whereas P. shigelloides exhibited distinct fermentation characteristics. All the isolated strains exhibited hemolytic activity; variable results of DNase, protease, and Congo red uptake tests; and resistance to ampicillin, bacitracin, novobiocin, penicillin, and vancomycin. All the strains were sensitive to amikacin, chloramphenicol, colistin, gentamicin, kanamycin, norfloxacin, and trimethoprim-sulfadimethoxazole. Because of the high proportion of asymptomatic carriers of these potentially pathogenic

Increased Pilus Production Conferred by a Naturally Occurring Mutation Alters Host-Pathogen Interaction in Favor of Carriage in Streptococcus pyogenes

PubMed Central

Olsen, Randall J.; Cantu, Concepcion; Pallister, Kyler B.; Guerra, Fermin E.; Voyich, Jovanka M.; Musser, James M.

2017-01-01

ABSTRACT Studies of the human pathogen group A Streptococcus (GAS) define the carrier phenotype to be an increased ability to adhere to and persist on epithelial surfaces and a decreased ability to cause disease. We tested the hypothesis that a single amino acid change (Arg135Gly) in a highly conserved sensor kinase (LiaS) of a poorly defined GAS regulatory system contributes to a carrier phenotype through increased pilus production. When introduced into an emm serotype-matched invasive strain, the carrier allele (the gene encoding the LiaS protein with an arginine-to-glycine change at position 135 [liaSR135G]) recapitulated a carrier phenotype defined by an increased ability to adhere to mucosal surfaces and a decreased ability to cause disease. Gene transcript analyses revealed that the liaS mutation significantly altered transcription of the genes encoding pilus in the presence of bacitracin. Elimination of pilus production in the isogenic carrier mutant decreased its ability to colonize the mouse nasopharynx and to adhere to and be internalized by cultured human epithelial cells and restored the virulence phenotype in a mouse model of necrotizing fasciitis. We also observed significantly reduced survival of the isogenic carrier mutant compared to that of the parental invasive strain after exposure to human neutrophils. Elimination of pilus in the isogenic carrier mutant increased the level of survival after exposure to human neutrophils to that for the parental invasive strain. Together, our data demonstrate that the carrier mutation (liaSR135G) affects pilus expression. Our data suggest new mechanisms of pilus gene regulation in GAS and that the invasiveness associated with pilus gene regulation in GAS differs from the enhanced invasiveness associated with increased pilus production in other bacterial pathogens. PMID:28264907

Differences in neurokinin receptor pharmacology between rat and guinea-pig superior cervical ganglia.

PubMed Central

Seabrook, G. R.; Main, M.; Bowery, B.; Wood, N.; Hill, R. G.

1992-01-01

1. The depolarizations elicited by seven neurokinin receptor agonists were examined in both rat and guinea-pig superior cervical ganglia by use of grease-gap methodology in the presence of tetrodotoxin (0.1 microM). Responses were normalised with respect to 1 microM eledoisin. 2. The rank order of agonist potency in the rat ganglia was senktide greater than substance P greater than substance P methyl ester = eleidosin = Sar-Met-substance P greater than neurokinin B greater than neurokinin A, whereas in guinea-pig superior cervical ganglion (SCG) the rank order was senktide greater than Sar-Met-substance P greater than neurokinin B = eledoisin = substance P methyl ester. The concentration-effect curves for substance P and neurokinin A in guinea-pig ganglia were biphasic which precluded the determination of meaningful potency values. 3. The maximal depolarization achieved by subtype selective ligands was different between these two species. On rat and guinea-pig SCG, the NK3-selective ligand, senktide, produced a maximal depolarization of 27% and 274% respectively, whereas the NK1-selective ligand, substance P methyl ester, produced depolarizations of 77% and 64% respectively. 4. The depolarizations induced by substance P methyl ester and senktide in either species were unaffected by atropine (1 microM), suggesting a lack of involvement of presynaptic neurokinin receptors in the generation of the response. 5. The potency of substance P methyl ester, senktide, and neurokinin A were unaffected by pretreating ganglia with the peptidase inhibitors bacitracin (40 micrograms ml-1), leupeptin (4 micrograms ml-1), and chymostatin (2 micrograms ml-1). Similarly, these peptidase inhibitors had no effect on the maximal depolarizations achieved by any of these agonists.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1380375

The Association of Race/Ethnicity and Patch Test Results: North American Contact Dermatitis Group, 1998-2006.

PubMed

Deleo, Vincent Anthony; Alexis, Andrew; Warshaw, Erin M; Sasseville, Denis; Maibach, Howard I; DeKoven, Joel; Zug, Kathryn A; Belsito, Donald V; Fowler, Joseph F; Marks, James G; Mathias, C G Toby; Pratt, Melanie D; Rietschel, Robert L; Storrs, Frances J; Taylor, James S; Zirwas, Matthew

2016-01-01

The North American Contact Dermatitis Group patch tests patients with suspected allergic contact dermatitis (ACD) to a broad series of screening allergens and publishes periodic reports. We have previously reported on the association of race and ethnicity with the rates of positive responses to standard patch test allergens. This report extends those observations. The aim of the study was to report the North American Contact Dermatitis Group patch testing results from January 1, 1998, to December 31, 2006, comparing the frequency of positive reactions between white and black subjects. Standardized patch testing with 45 allergens was used at 13 centers in North America. χ analysis of results in black subjects as compared with whites was examined. A total of 19,457 patients were tested; 92.9% (17,803) were white and 7.1% (1,360) were black. The final diagnoses of ACD (whites, 45.9%; blacks, 43.6%) and irritant contact dermatitis (13.0%/13.3%) were similar in the 2 groups. The diagnosis of atopic dermatitis was less common in the white patients (8.9%) as compared with the black patients (13.3%). Positive patch test reactions rates were similar for most allergens. However, statistically, blacks reacted more frequently to p-phenylenediamine (7.0% vs 4.4%, P < 0.001), bacitracin (11.6% vs 8.3%, P = 0.0004), as well as specific rubber accelerators mercaptobenzothiazole (2.7% vs 1.8%), thiuram (6.2% vs 4.3%), and mercapto mix (1.9% vs 0.8%, P < 0.001). Whites had an increase in positive reactions to fragrances (12.12% vs 6.77%, P < 0.0001), formaldehyde (9.25% vs 5.45%, P < 0.0001), and some formaldehyde releaser preservatives used in personal care products and textile resins (9.80% vs 6.18%, P < 0.0001). There were statistically different rates of positive patch test reactions to specific allergens between black and white patients suspected of having ACD. The etiology of these differences is unclear but probably relates to culturally determined exposure patterns rather

Local and systemic innate immunity in broiler chickens supplemented with yeast-derived carbohydrates.

PubMed

Munyaka, P M; Echeverry, H; Yitbarek, A; Camelo-Jaimes, G; Sharif, S; Guenter, W; House, J D; Rodriguez-Lecompte, J C

2012-09-01

A study was conducted to assess the effect of yeast-derived carbohydrates (YDC) on performance and innate immune responses of broiler chickens. In total, 1,080 one-day-old birds were randomly assigned to one of 3 dietary treatments (n = 360): a standard broiler diet containing monensin (control), control + bacitracin methylene disalycylate (BMD), and YDC treatment (control + YDC at 0.02%, 0.01%, and 0.005% for starter, grower, and finisher, respectively). Weekly BW, feed intake (FI), and feed conversion ratio (FCR) were recorded. Immune organ weights, gut morphology, gene expression, heterophil:lymphocyte (H:L), and serum IgG were determined at d 42. No significant difference in FCR, FI, and mortality was observed among treatments. However, BW gain in starter phase was higher in control and YDC treatments compared with BMD treatment. Ileal villi height, crypt depth, and their ratio were not significantly different among treatments, whereas villi width was lower in control and YDC treatments compared with BMD treatment. The number of goblet cells per unit area in the ileum was lower in BMD treatment compared with control and YDC treatments. Expression of TLR2b and IL-6 in the ileum and cecal tonsils was not significantly different among treatments (P > 0.05). Expression of TLR4 was downregulated in YDC treatment compared with control in the ileum. Expression of IL-12p35 and IFN-γ were downregulated in the YDC treatment only in the cecal tonsils. Compared with the control, the expression of IL-10 in both the ileum and the cecal tonsils was downregulated in YDC treatment. Serum IgG and H:L ratio were lower and higher, respectively, in the YDC treatment compared with control and BMD treatments. In conclusion, dietary inclusion of YDC affected intestinal cytokines anti-inflammatory profile on a gut location associated immune pathways manner, suggesting different immune pathways that require further studies in this field.

Anti-microbial Activity of Tulsi {Ocimum Sanctum (Linn.)} Extract on a Periodontal Pathogen in Human Dental Plaque: An Invitro Study

PubMed Central

Devaraj, C.G.; Agarwal, Payal

2016-01-01

Introduction Tulsi is a popular healing herb in Ayurvedic medicine. It is widely used in the treatment of several systemic diseases because of its anti-microbial property. However, studies documenting the effect of Tulsi on oral disease causing organisms are rare. Hence, an attempt was made to determine the effect of Tulsi on a periodontal microorganism in human dental plaque. Aim To determine if Ocimum sanctum (Linn.) has an anti-microbial activity (Minimum Inhibitory Concentration and zone of inhibition) against Actinobacillus actinomycetemcomitans in human dental plaque and to compare the antimicrobial activity of Ocimum sanctum(Linn.) extract with 0.2% chlorhexidine as the positive control and dimethyl sulfoxide as the negative control. Materials and Methods A lab based invitro experimental study design was adopted. Ethanolic extract of Ocimum sanctum (Linn.) was prepared by the cold extraction method. The extract was diluted with an inert solvent, dimethyl sulfoxide, to obtain ten different concentrations (1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%) of extract. Plaque sample was collected from 05 subjects diagnosed with periodontal disease. Isolation of Actinobacillus actinomycetemcomitans from plaque samples was done using Tryptic Soy Serum Bacitracin Vancomycin agar (TSBV) medium. Identification of Actinobacillus actinomycetemcomitans was done based on cultural, microscopic, biochemical characterization and multiple drug resistance patterns. Anti-microbial activity of Ocimum sanctum (Linn.) extract was tested by agar well-diffusion method against 0.2% chlorhexidine as a positive control and dimethyl sulfoxide as a negative control. The zone of inhibition was measured in millimeters using Vernier callipers. Results At the 6% w/v concentration of Ocimum sanctum (Linn.) extract, a zone of inhibition of 22 mm was obtained. This was the widest zone of inhibition observed among all the 10 different concentrations tested. The zone of inhibition for positive control

Effects of diets containing different concentrations of mannanoligosaccharide or antibiotics on growth performance, intestinal development, cecal and litter microbial populations, and carcass parameters of broilers.

PubMed

Baurhoo, B; Ferket, P R; Zhao, X

2009-11-01

The effects of 2 levels of mannanoligosaccharide (MOS) in feed were compared with antibiotic growth promoters on growth performance, intestinal morphology, cecal and litter microbial populations, and carcass parameters in broilers raised in a sanitary environment. Dietary treatments included: 1) antibiotic growth promoter-free diet (control), 2) VIRG (diet 1 + 16.5 mg/kg of virginiamycin), 3) BACT (diet 1 + 55 mg/kg of bacitracin), 4) LMOS (diet 1 + 0.2% MOS), and 5) HMOS (diet 1 + 0.5% MOS). Birds were randomly assigned to 3 replicate pens/treatment (n = 55/pen). Body weight and feed intake were recorded weekly throughout 38 d. At d 14, 24, and 34, a 1-cm segment of duodenum, jejunum, and ileum was used in morphological analysis (n = 9 birds/d per treatment). At the same bird ages, cecal contents were assayed for lactobacilli, bifidobacteria, Salmonella, Campylobacter, and Escherichia coli, whereas litter was analyzed for Salmonella, Campylobacter, and E. coli. Carcass yields (breast fillet and tenders, thigh, drumstick, and wing) were determined at d 38. Body weight, feed conversion, and carcass yields did not differ among treatments. In contrast to birds fed VIRG or BACT, LMOS and HMOS consistently increased (P < 0.05) villi height and goblet cell number per villus in all intestinal segments at d 24 and 34. Bifidobacteria concentrations were higher (P < 0.05) in LMOS- and HMOS-fed birds at all time points. Birds and litter from all treatments were free of Salmonella. At d 14 and 24, cecal E. coli and Campylobacter counts were not different among treatments. In comparison to birds fed control, at d 34, BACT, LMOS, and HMOS significantly reduced (P < 0.05) cecal E. coli concentrations, whereas Campylobacter counts were reduced (P < 0.05) by VIRG, BACT, and LMOS. Litter bacterial counts were not altered by dietary treatments. In conclusion, under conditions of this study, MOS conferred intestinal health benefits to chickens by improving its morphological

Incisionless otoplasty: a reliable and replicable technique for the correction of prominauris.

PubMed

Mehta, Shaun; Gantous, Andres

2014-01-01

This study evaluates the postoperative outcomes achieved with incisionless otoplasty for the correction of prominauris. To determine whether incisionless otoplasty is a reliable and replicable technique in correcting prominauris. This study consisted of a retrospective electronic medical record review for 72 patients undergoing incisionless otoplasty for the correction of prominauris by a single surgeon from November 2006 to April 2013. Follow-up ranged from 1 to 87 months. The patients were operated on at both St Joseph's Health Centre (a community hospital) and The Cumberland Clinic (private practice) in Toronto, Ontario, Canada. All patients undergoing an incisionless otoplasty for the correction of prominauris were eligible. Participants' ages ranged from 3 to 55 years, with the majority being adults. Seventy patients were followed up for outcomes. Incisionless otoplasty. Number and type of sutures used, perioperative complications, and postoperative follow-up including complications and revisions. Complications included infection, hematoma, bleeding, perichondritis, suture granuloma, suture exposure, and suture failure. A mean (SD) 2.5 (0.8) sutures were used in the left ear, 2.48 (0.75) in the right ear, and 4.69 (1.75) in total. The number of sutures used in the left vs right ear was not significantly different (P = .60). All patients had horizontal mattress sutures placed for correction of prominauris. There were no serious perioperative complications such as infection, bleeding, hematoma, perichondritis, or cartilage necrosis. Follow-up data were extracted and analyzed in 70 patients, with a mean follow-up time of 31 months. Complications were seen in 10 patients (14%): 4 were due to suture failure, 3 were due to suture exposure, 2 were due to granuloma formation, and 1 was due to a Polysporin (bacitracin zinc/polymyxin B sulfate) reaction. Nine patients (13%) needed a revision to achieve a desirable result. The technique of incisionless otoplasty used

Use of Bacillus Subtilis PB6 as a potential antibiotic growth promoter replacement in improving performance of broiler birds.

PubMed

Jayaraman, Sathishkumar; Das, Partha Pratim; Saini, Prakash Chandra; Roy, Barun; Chatterjee, Paresh Nath

2017-08-01

The intestinal gut health is one of the primary determinants of broiler growth and performance. Among the various enteric diseases, necrotic enteritis (NE) is an enterotoxemic disease caused by Clostridium perfringens, which can result in severe economic losses in poultry farming. Antibiotics like bacitracin methylene disalicylate (BMD) and avilamycin (AVL) are commonly used antibiotic growth promoters (AGP) in poultry feed to control necrotic enteritis in birds. Bacillus subtilis PB6 was reported to prevent necrotic enteritis and improve performance in birds. This paper investigated the influence of Bacillus subtilis PB6 in improving the performance of broiler birds in comparison with BMD and avilamycin. A 35 day trial was conducted with 240 day-old commercial broiler chicks (VenCobb 400), which were divided into four treatment groups, where each treatment group was composed of 6 replicates each containing 10 birds, for a total of 60 birds per treatment. The treatment groups included a negative control (no AGP), Bacillus subtilis PB6, BMD, and avilamycin. The parameters analyzed included body weight, feed conversion ratio (FCR), mortality, villus histomorphometry, and European efficiency factor (EEF). Bacillus subtilis PB6 significantly (P < 0.05) improved body weight and FCR (8 points) compared to the control. The group supplemented with B. subtilis PB6 or BMD had higher (P < 0.05) body weight compared to all other treatment groups. The supplementation of B. subtilis PB6 significantly improved the villus height (P < 0.05) compared to control and other AGP groups. The EEF was found to be the highest in the B. subtilis PB6 supplemented group at 35th day as compared to other treatment groups. The combined data from this study indicate that supplementation of B. subtilis PB6 improves overall performance of broilers compared to BMD and avilamycin, and can be used as potential AGP replacement in poultry farming. © 2017 Poultry Science Association Inc.

Efficacy of Neem Extract and Three Antimicrobial Agents Incorporated into Tissue Conditioner in Inhibiting the Growth of C. Albicans and S. Mutans

PubMed Central

Barua, Dikshita Ray; Varghese, Rana Kalappattil

2017-01-01

Introduction Denture stomatitis is an inflammatory condition which compromises the mucosal surface beneath dentures. The aetiology of denture stomatitis is usually multifactorial which varies from trauma from ill fitting denture to poor immune system. There are evidences that denture stomatitis is an outcome of multispecies biofilms that include Candida albicans and Streptococcus mutans. Tissue conditioners are found to be more susceptible to colonisation by micro-organisms. Aim The purpose of this study was to compare the efficacy of neem leaf extract and three other antimicrobial agents incorporated in a tissue conditioner against both Candida albicans and Streptococcus mutans. Materials and Methods Standard strain of Candida albicans and Streptococcus mutans were inoculated into Sabouraud Dextrose broth and Mitis-Salivarius-Bacitracin broth respectively incubated at 37°C. Tissue conditioner (Viscogel) mixed with two different concentrations of ketoconazole, nystatin and chlorhexidine diacetate (5%, 10% w/w) and neem leaf extract (7.5% w/w and 15% w/w) and control group (plain tissue conditioner) were placed into punch hole (6 mm diameter) agar plate inoculated with Candida albicans and Streptococcus mutans. A total of 216 samples were prepared for both Candida albicans and Streptococcus mutans. Mean Inhibition Diameter (MID) across each punch holes were measured in millimetres at 24 hours and seven days and data were statistically analysed using Kruskal Wallis test followed by Mann-Whitney U test. Results Both ketoconazole and nystatin (10% w/w) showed maximum inhibition of 32 mm and mean of 31.75 followed by 15% w/w neem leaf extract with an inhibition of 21 mm and mean of 20.67 after 24 hours against Candida albicans whereas chlorhexidine diacetate (10% w/w) showed mean of 25.67 followed by chlorhexidine diacetate (5% w/w) and neem extract (15% w/w) which showed mean of 24.17 and 23.67 respectively against Streptococcus mutans. Conclusion Neem leaf extract

Phytogenic Feed Additives as an Alternative to Antibiotic Growth Promoters in Broiler Chickens

PubMed Central

Murugesan, Ganapathi Raj; Syed, Basharat; Haldar, Sudipto; Pender, Chasity

2015-01-01

The recent trend toward reduction of antibiotic growth promoters (AGP) in North American poultry diets has put tremendous pressure on the industry to look for viable alternatives. In this context, phytogenic feed additives (PFA) are researched to improve gut health and thereby performance. An experiment was conducted with the objective to evaluate the effects of PFA as an alternative to AGP on small intestinal histomorphology, cecal microbiota composition, nutrient digestibility, and growth performance in broiler chickens. A total of 432-day-old Vencobb 400 broiler chicks were randomly assigned to one of three dietary groups, each consisting of 12 replicate pens (n = 12 chicks/pen). The chicks were fed a corn–soybean meal-based control (CON), CON + 500 mg/kg of AGP (bacitracin methylene disalicylate containing 450 mg active BMD/g), or CON + 150 mg/kg of proprietary blend of PFA (Digestarom® Poultry) until 39 days of age when samples were collected. Birds fed either AGP or PFA had increased villus height in all three segments of the small intestine in comparison to the birds fed CON (P ≤ 0.05). Furthermore, the PFA-fed birds had significantly increased villus height and lower crypt depth compared to AGP fed birds (P ≤ 0.05). Birds fed either additive also had increased total tract digestibility of dry matter, crude protein, and ether extract (P ≤ 0.05). The strong effect of the PFA on villus height in the jejunum may suggest augmented nutrient absorption in PFA-fed birds. Although both additives reduced total cecal counts of anaerobic bacteria and Clostridium spp., PFA alone reduced the total coliform count while increasing the Lactobacillus spp. count (P ≤ 0.05). These results suggest the establishment of beneficial microbial colonies in PFA-fed birds. Overall, both PFA and AGP increased body weight gain while lowering the feed conversion ratio (P ≤ 0.05). Hence data from this experiment demonstrate the efficacy

A comparative evaluation of Oratest with the microbiological method of assessing caries activity in children

PubMed Central

Sundaram, Meenakshi; Nayak, Ullal Anand; Ramalingam, Krishnakumar; Reddy, Venugopal; Rao, Arun Prasad; Mathian, Mahesh

2013-01-01

Aims: The aim of this study is to find out whether Oratest can be used as a diagnostic tool in assessing the caries activity by evaluating its relationship to the existing caries status and the salivary streptococcus mutans level. Materials and Methods: The study sample consists of 90 students divided into two groups. Group I (test group) and Group II (control group) consisting of 30 children for control group and 60 children for test group. The sampling of unstimulated saliva for the estimation of streptococcus mutans was done as per the method suggested by Kohler and Bratthall. The plates were then incubated. Rough surface colonies were identified as streptococcus mutans on a pre-determined area of the tip (approximately 1.5 cm2) were counted for each side of spatula pressed against mitis salivarius bacitracin agar using digital colony counter. The results were expressed in colony forming units (CFU). Oratest was carried out in the same patients after the collection of salivary sample for the microbiological method to evaluate the relationship between the two tests. Statistical Analysis Used: The tests used were ANOVA, Pearson Chi-square test, Pearson′s correlation analysis, Mann-Whitney U test and Student′s independent t-test. Results: In the control group and test group, when the streptococcus mutans count (CFU) and Oratest time (minutes) were correlated using Pearson′s correlation analysis, the streptococcus mutans counts was found to be in a statistically significant negative linear relationship with the Oratest time. When the caries status of the children, participated in the test group were correlated with mutans count (CFU) and Oratest time, caries status were found to be in a statistically significant positive linear relationship with streptococcus mutans count and in a significant negative linear relationship with Oratest time. Conclusions: The test proved to be a simple, inexpensive and rapid technique for assessing caries activity since a

The sensitivity and the specifity of rapid antigen test in streptococcal upper respiratory tract infections.

PubMed

Gurol, Yesim; Akan, Hulya; Izbirak, Guldal; Tekkanat, Zuhal Tazegun; Gunduz, Tehlile Silem; Hayran, Osman; Yilmaz, Gulden

2010-06-01

It is aimed to detect the sensitivity and specificity of rapid antigen detection of group A beta hemolytic streptococci from throat specimen compared with throat culture. The other goal of the study is to help in giving clinical decisions in upper respiratory tract infections according to the age group, by detection of sensitivity and positive predictive values of the rapid tests and throat cultures. Rapid antigen detection and throat culture results for group A beta hemolytic streptococci from outpatients attending to our university hospital between the first of November 2005 and 31st of December 2008 were evaluated retrospectively. Throat samples were obtained by swabs from the throat and transported in the Stuart medium and Quickvue Strep A [Quidel, San Diego, USA] cassette test was applied and for culture, specimen was inoculated on 5% blood sheep agar and identified according to bacitracin and trimethoprim-sulphametaxazole susceptibility from beta hemolytic colonies. During the dates between the first of November 2005 and 31st of December 2008, from 453 patients both rapid antigen detection and throat culture were evaluated. Rapid antigen detection sensitivity and specificity were found to be 64.6% and 96.79%, respectively. The positive predictive value was 80.95% whereas negative predictive value was 92.82%. Kappa index was 0.91. When the results were evaluated according to the age groups, the sensitivity and the positive predictive value of rapid antigen detection in children were 70%, 90.3% and in adults 59.4%, 70.4%. When bacterial infection is concerned to prevent unnecessary antibiotic use, rapid streptococcal antigen test (RSAT) is a reliable method to begin immediate treatment. To get the maximum sensitivity of RSAT, the specimen collection technique used and education of the health care workers is important. While giving clinical decision, it must be taken into consideration that the sensitivity and the positive predictive value of the RSAT is quite

An evaluation of the role of a pyroglutamyl peptidase, a post-proline cleaving enzyme and a post-proline dipeptidyl amino peptidase, each purified from the soluble fraction of guinea-pig brain, in the degradation of thyroliberin in vitro.

PubMed

Browne, P; O'Cuinn, G

1983-12-01

The degradation of thyroliberin (less than Glu-His-Pro-NH2) to its component amino acids by the soluble fraction of guinea pig brain is catalysed by four enzymes namely a pyroglutamate aminopeptidase, a post-proline cleaving enzyme, a post-proline dipeptidyl aminopeptidase and a proline dipeptidase. 1. The pyroglutamate aminopeptidase was purified to over 90% homogeneity with a purification factor of 2868-fold and a yield of 5.7%. In addition to catalysing the hydrolysis of thyroliberin, acid thyroliberin and pyroglutamate-7-amido-4-methylcoumarin the pyroglutamate aminopeptidase catalysed the hydrolysis of the peptide bond adjacent to the pyroglutamic acid residue in luliberin, neurotensin bombesin, bradykinin-potentiating peptide B, the anorexogenic peptide and the dipeptides pyroglutamyl alanine and pyroglutamyl valine. Pyroglutamyl proline and eledoisin were not hydrolysed. 2. The post-proline cleaving enzyme was purified to apparent electrophoretic homogeneity with a purification factor of 2298-fold and a yield of 10.6%. The post-proline cleaving enzyme catalysed the hydrolysis of thyroliberin and N-benzyloxycarbonyl-glycylproline-7-amido-4-methylcoumarin. It did not catalyse the hydrolysis of glycylproline-7-amido-4-methylcoumarin or His-Pro-NH2. 3. The post-proline dipeptidyl aminopeptidase was partially purified with a purification factor of 301-fold and a yield of 8.9%. The post-proline dipeptidyl aminopeptidase catalysed the hydrolysis of His-Pro-NH2 and glycylproline-7-amido-4-methylcoumarin but did not exhibit any post-proline cleaving endopeptidase activity against thyroliberin or N-benzyloxycarbonyl-glycylproline-7-amido-4-methylcoumarin. 4. Studies with various functional reagents indicated that the pyroglutamate aminopeptidase could be specifically inhibited by 2-iodoacetamide (100% inhibition at an inhibitor concentration of 5 microM), the post-proline cleaving enzyme by bacitracin (IC50 = 42 microM) and the post-proline dipeptidyl aminopeptidase

Anti-microbial Activity of Tulsi {Ocimum Sanctum (Linn.)} Extract on a Periodontal Pathogen in Human Dental Plaque: An Invitro Study.

PubMed

Eswar, Pranati; Devaraj, C G; Agarwal, Payal

2016-03-01

Tulsi is a popular healing herb in Ayurvedic medicine. It is widely used in the treatment of several systemic diseases because of its anti-microbial property. However, studies documenting the effect of Tulsi on oral disease causing organisms are rare. Hence, an attempt was made to determine the effect of Tulsi on a periodontal microorganism in human dental plaque. To determine if Ocimum sanctum (Linn.) has an anti-microbial activity (Minimum Inhibitory Concentration and zone of inhibition) against Actinobacillus actinomycetemcomitans in human dental plaque and to compare the antimicrobial activity of Ocimum sanctum(Linn.) extract with 0.2% chlorhexidine as the positive control and dimethyl sulfoxide as the negative control. A lab based invitro experimental study design was adopted. Ethanolic extract of Ocimum sanctum (Linn.) was prepared by the cold extraction method. The extract was diluted with an inert solvent, dimethyl sulfoxide, to obtain ten different concentrations (1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%) of extract. Plaque sample was collected from 05 subjects diagnosed with periodontal disease. Isolation of Actinobacillus actinomycetemcomitans from plaque samples was done using Tryptic Soy Serum Bacitracin Vancomycin agar (TSBV) medium. Identification of Actinobacillus actinomycetemcomitans was done based on cultural, microscopic, biochemical characterization and multiple drug resistance patterns. Anti-microbial activity of Ocimum sanctum (Linn.) extract was tested by agar well-diffusion method against 0.2% chlorhexidine as a positive control and dimethyl sulfoxide as a negative control. The zone of inhibition was measured in millimeters using Vernier callipers. At the 6% w/v concentration of Ocimum sanctum (Linn.) extract, a zone of inhibition of 22 mm was obtained. This was the widest zone of inhibition observed among all the 10 different concentrations tested. The zone of inhibition for positive control was 25mm and no zone of inhibition was observed

North American Contact Dermatitis Group patch test results for 2007-2008.

PubMed

Fransway, Anthony F; Zug, Kathryn A; Belsito, Donald V; Deleo, Vincent A; Fowler, Joseph F; Maibach, Howard I; Marks, James G; Mathias, C G Toby; Pratt, Melanie D; Rietschel, Robert L; Sasseville, Denis; Storrs, Frances J; Taylor, James S; Warshaw, Erin M; Dekoven, Joel; Zirwas, Matthew

2013-01-01

The North American Contact Dermatitis Group (NACDG) tests patients with suspected allergic contact dermatitis to a broad series of screening allergens and publishes periodic reports. The aims of this study were to report the NACDG patch-testing results from January 1, 2007, to December 31, 2008, and to compare results to pooled test data from the previous 2 and 10 years to analyze trends in allergen sensitivity. Standardized patch testing with 65 allergens was used at 13 centers in North America. χ analysis was used for comparisons. A total of 5085 patients were tested; 11.8% (598) had an occupationally related skin condition, and 65.3% (3319) had at least 1 allergic patch test reaction, which is identical to the NACDG data from 2005 to 2006. The top 15 most frequently positive allergens were nickel sulfate (19.5%), Myroxylon pereirae (11.0%), neomycin (10.1%), fragrance mix I (9.4%), quaternium-15 (8.6%), cobalt chloride (8.4%), bacitracin (7.9%), formaldehyde (7.7%), methyldibromoglutaronitrile/phenoxyethanol (5.5%), p-phenylenediamine (5.3%), propolis (4.9%), carba mix (4.5%), potassium dichromate (4.1%), fragrance mix II (3.6%), and methylchloroisothiazolinone/methylisothiazolinone (3.6%). There were significant increases in positivity rates to nickel, methylchloroisothiazolinone/methylisothiazolinone, and benzophenone-3. During the same period of study, there were significant decreases in positivity rates to neomycin, fragrance mix I, formaldehyde, thiuram mix, cinnamic aldehyde, propylene glycol, epoxy resin, diazolidinyl urea, amidoamine, ethylenediamine, benzocaine, p-tert-butylphenol formaldehyde resin, dimethylol dimethyl hydantoin, cocamidopropyl betaine, glutaraldehyde, mercaptobenzothiazole, tosylamide formaldehyde resin, budesonide, disperse blue 106, mercapto mix, and chloroxylenol. Twenty-four percent (1221) had a relevant positive reaction to a non-NACDG supplementary allergen; and 180 of these reactions were occupationally relevant. Periodic

Differences in neurokinin receptor pharmacology between rat and guinea-pig superior cervical ganglia.

PubMed

Seabrook, G R; Main, M; Bowery, B; Wood, N; Hill, R G

1992-04-01

1. The depolarizations elicited by seven neurokinin receptor agonists were examined in both rat and guinea-pig superior cervical ganglia by use of grease-gap methodology in the presence of tetrodotoxin (0.1 microM). Responses were normalised with respect to 1 microM eledoisin. 2. The rank order of agonist potency in the rat ganglia was senktide greater than substance P greater than substance P methyl ester = eleidosin = Sar-Met-substance P greater than neurokinin B greater than neurokinin A, whereas in guinea-pig superior cervical ganglion (SCG) the rank order was senktide greater than Sar-Met-substance P greater than neurokinin B = eledoisin = substance P methyl ester. The concentration-effect curves for substance P and neurokinin A in guinea-pig ganglia were biphasic which precluded the determination of meaningful potency values. 3. The maximal depolarization achieved by subtype selective ligands was different between these two species. On rat and guinea-pig SCG, the NK3-selective ligand, senktide, produced a maximal depolarization of 27% and 274% respectively, whereas the NK1-selective ligand, substance P methyl ester, produced depolarizations of 77% and 64% respectively. 4. The depolarizations induced by substance P methyl ester and senktide in either species were unaffected by atropine (1 microM), suggesting a lack of involvement of presynaptic neurokinin receptors in the generation of the response. 5. The potency of substance P methyl ester, senktide, and neurokinin A were unaffected by pretreating ganglia with the peptidase inhibitors bacitracin (40 micrograms ml-1), leupeptin (4 micrograms ml-1), and chymostatin (2 micrograms ml-1). Similarly, these peptidase inhibitors had no effect on the maximal depolarizations achieved by any of these agonists.6. It is evident that rat and guinea-pig superior cervical ganglia possess both NK, and NK3 receptors, but that their net contribution to depolarizations are different between the two species. The depolarizations

Radioligand binding, autoradiographic and functional studies demonstrate tachykinin NK-2 receptors in dog urinary bladder.

PubMed

Mussap, C J; Stamatakos, C; Burcher, E

1996-10-01

Tachykinin receptors in the dog bladder were characterized using radioligand binding, functional and autoradiographic techniques. In detrusor muscle homogenates, specific binding of [125l]iodohistidyl neurokinin A (INKA) and [125l]Bolton Hunter eledoisin was reversible, saturable and, to a single class of sites of Kd, 3,6 and 27 nM, respectively. No specific binding of [125l]Bolton Hunter[Sar9, Met (O2)11] substance P occurred. INKA binding was reduced by the peptidase inhibitor bacitracin. The rank potency order of agonists competing for binding of both radioligands indicated interaction at NK-2 sites. NK-2-selective antagonists also competed for INKA binding, with SR 48968, GR 94800, MDL 29913 and the selective agonist [Lys5, MeLeu9, Nle10]-NKA(4-10) showing biphasic binding profiles. Autoradiographic studies revealed specific binding of INKA and [125l]Bolton Hunter eledoisin over detrusor muscle and small arteries. [125l]Bolton Hunter [Sar9, Met (O2)11] SP labeled the intima of arteries and arterioles, but not the detrusor muscle. Tachykinins contracted detrusor muscle strips, with potency order at the carbachol EC15 NKA = kassinin > [Lys5, MeLeu9, Nle10]-NKA(4-10) = neuropeptide gamma = neuropeptide K = NKB > > MDL 28564, with [Sar9, Met(O2)11]-SP ineffective. Shallow concentration-response curves, variable efficacies and inhibition by atropine and mepyramine suggest that other mechanisms may influence contractile responses. Responses to [Lys5, MeLeu9, Nle10]-NKA(4-10) were inhibited competitively by MDL 29913 and MEN 10207 (pA2 values: 6.4 and 5.3, respectively). Antagonism by SR 48968 and GR 94800 was noncompetitive (both pK8 values 8.9). In summary, NK-2-preferring ligands showed superior potency as both binding competitors and contractile agonists, demonstrating that NK-2 receptors mediate detrusor muscle contraction, similar to the human detrusor. Tachykinins may play important roles in the micturition reflex and in regulating detrusor muscle blood flow in

Luteinizing hormone-releasing hormone inactivation by purified pituitary plasma membranes: effects of receptor-binding studies.

PubMed

Clayton, R N; Shakespear, R A; Duncan, J A; Marshall, J C

1979-05-01

Inactivation of LHRH by purified bovine pituitary plasma membranes was studied in vitro. After incubation of [125I]iodo-LHRH with plasma membranes, the amount of tracer bound to the pellet was measured, and the integrity of the unbound tracer in the supernatant was assessed. Reduction in ability to bind to anti-LHRH serum and to rebind to plasma membranes together with altered electrophoretic mobility on polyacrylamide gels showed that the unbound [125I]iodo-LHRH was inactivated. LHRH inactivation occurred rapidly and was dependent upon membrane concentration and incubation temperature. These results indicate that hormone inactivation must be taken into account in the interpretation of LHRH-receptor interactions. During 37 C incubations, the apparent absence of specific LHRH binding can be explained by inactivation of tracer hormone. Significant LHRH inactivation also occurred at 0 C, which in part explains the insensitivity of LHRH receptor assays. Assessment of LHRH inactivation by different particulate subcellular fractions of pituitary tissue showed that the inactivating enzyme was associated with the plasma membranes; other organelles did not alter LHRH. The enzyme appeared to be an integral part of the plasma membrane structure, since enzymic activity could not be removed by washing without reducing specific LHRH binding. Additionally, reduction of LHRH inactivation by the inhibitors Bacitracin and Trasylol and by magnesium was also accompanied by reduced LHRH binding. Previous studies have shown that the majority of LHRH binding to pituitary plasma membranes is to the low affinity site (approximately 10(-6) M), but the significance of this binding has been uncertain. Our findings indicate that low affinity binding probably represents binding of LHRH to the inactivating enzyme. The LHRH analog, D-Ser6(TBu), des Gly10, ethylamide, has greater biological activity than LHRH and is not inactivated to a significant extent by pituitary plasma membranes. The

Evaluation of probiotic properties of Lactobacillus plantarum WLPL04 isolated from human breast milk.

PubMed

Jiang, Meiling; Zhang, Fen; Wan, Cuixiang; Xiong, Yonghua; Shah, Nagendra P; Wei, Hua; Tao, Xueying

2016-03-01

Lactobacillus plantarum WLPL04, a specific strain isolated from human breast milk, was investigated for its survival capacity (acid and bile salt tolerance, survival in simulated gastrointestinal tract, inhibition of pathogens, antibiotic susceptibility, yield of exopolysaccharides) and probiotic properties (antiadhesion of pathogens, protection from harmful effect of sodium dodecyl sulfate, and antiinflammatory stress on Caco-2 cells). The results showed that Lb. plantarum WLPL04 had broad-spectrum activity against gram-positive strains (Listeria monocytogenes CMCC54007, Bacillus cereus ATCC14579, and Staphylococcus aureus CMCC26003) and gram-negative strains (Pseudomonas aeruginosa MCC10104, Shigella sonnei ATCC25931, Enterobacter sakazakii ATCC29544, Salmonella typhimurium ATCC13311, and Escherichia coli O157:H7). Antibiotic susceptibility tests showed that Lb. plantarum WLPL04 was susceptible to 8 of 14 antibiotics (e.g., erythromycin and nitrofurantoin) and resistant to 6 of 14 antibiotics (e.g., kanamycin and bacitracin). Lactobacillus plantarum WLPL04 was able to survive at pH 2.5 for 3h and at 0.45% bile salt for 12h, suggesting that it can survive well in the gastrointestinal tract. In addition, the exopolysaccharide yield of Lb. plantarum WLPL04 reached 426.73 ± 65.56 mg/L at 24h. With strategies of competition, inhibition, and displacement, Lb. plantarum WLPL04 reduced the adhesion of E. coli O157:H7 (35.51%), Sal. typhimurium ATCC 13311 (8.10%), and Staph. aureus CMCC 26003 (40.30%) on Caco-2 cells by competition, and subsequently by 59.80, 62.50, and 42.60%, respectively, for the 3 pathogens through inhibition, and by 75.23, 39.97, and 52.88%, respectively, through displacement. Lactobacillus plantarum WLPL04 attenuated the acute stress induced by sodium dodecyl sulfate on Caco-2 cells and significantly inhibited the expression of inflammatory cytokines (IL-6, IL-8 and tumor necrosis factor-α) on Caco-2 cells but increased IL-10 expression in vitro

Optimal antidiarrhea treatment for antitumor agent irinotecan hydrochloride (CPT-11)-induced delayed diarrhea.

PubMed

Takasuna, K; Hagiwara, T; Watanabe, K; Onose, S; Yoshida, S; Kumazawa, E; Nagai, E; Kamataki, T

2006-10-01

An antitumor camptothecin derivative CPT-11 has proven a broad spectrum of solid tumor malignancy, but its severe diarrhea has often limited its more widespread use. We have demonstrated from a rat model that intestinal beta-glucuronidase may play a key role in the development of CPT-11-induced delayed diarrhea by the deconjugation of the luminal SN-38 glucuronide, and the elimination of the intestinal microflora by antibiotics or dosing of TJ-14, a Kampo medicine that contains beta-glucuronidase inhibitor baicalin, exerted a protective effect. In the present study, we assessed the efficacy of several potential treatments in our rat model to clarify which is the most promising treatment for CPT-11-induced delayed diarrhea. Oral dosing (twice daily from days -1 to 4) of streptomycin 20 mg/kg and penicillin 10 mg/kg (Str/Pen), neomycin 20 mg/kg and bacitracin 10 mg/kg (Neo/Bac), both of which inhibited almost completely the fecal beta-glucuronidase activity, or TJ-14 1,000 mg/kg improved the decrease in body weight and the delayed diarrhea symptoms induced by CPT-11 (60 mg/kg i.v. from days 1 to 4) to a similar extent. The efficacy was less but significant in activated charcoal (1,000 mg/kg p.o. twice daily from days -1 to 4). In a separate experiment using rats bearing breast cancer (Walker 256-TC), TJ-14, Neo/Bac, and charcoal at the same dose regimen improved CPT-11-induced intestinal toxicity without reducing CPT-11's antitumor activity. In contrast, oral dosing (twice a day) of cyclosporin A (50 mg/kg), a P-glycoprotein and cMOAT/MRP2 inhibitor or valproic acid (200 mg/kg), a UDP-glucuronosyltranferase inhibitor, exacerbated the intestinal toxicity without modifying CPT-11's antitumor activity. The result clearly demonstrated the ability of Neo/Bac, Str/Pen, and TJ-14, less but significant ability of activated charcoal, to ameliorate CPT-11-induced delayed-onset diarrhea, suggesting the treatments decreasing the exposure of the intestines to the luminal SN-38

Comparative genomics of Clostridium bolteae and Clostridium clostridioforme reveals species-specific genomic properties and numerous putative antibiotic resistance determinants.

PubMed

Dehoux, Pierre; Marvaud, Jean Christophe; Abouelleil, Amr; Earl, Ashlee M; Lambert, Thierry; Dauga, Catherine

2016-10-21

Clostridium bolteae and Clostridium clostridioforme, previously included in the complex C. clostridioforme in the group Clostridium XIVa, remain difficult to distinguish by phenotypic methods. These bacteria, prevailing in the human intestinal microbiota, are opportunistic pathogens with various drug susceptibility patterns. In order to better characterize the two species and to obtain information on their antibiotic resistance genes, we analyzed the genomes of six strains of C. bolteae and six strains of C. clostridioforme, isolated from human infection. The genome length of C. bolteae varied from 6159 to 6398 kb, and 5719 to 6059 CDSs were detected. The genomes of C. clostridioforme were smaller, between 5467 and 5927 kb, and contained 5231 to 5916 CDSs. The two species display different metabolic pathways. The genomes of C. bolteae contained lactose operons involving PTS system and complex regulation, which contribute to phenotypic differentiation from C. clostridioforme. The Acetyl-CoA pathway, similar to that of Faecalibacterium prausnitzii, a major butyrate producer in the human gut, was only found in C. clostridioforme. The two species have also developed diverse flagella mobility systems contributing to gut colonization. Their genomes harboured many CDSs involved in resistance to beta-lactams, glycopeptides, macrolides, chloramphenicol, lincosamides, rifampin, linezolid, bacitracin, aminoglycosides and tetracyclines. Overall antimicrobial resistance genes were similar within a species, but strain-specific resistance genes were found. We discovered a new group of genes coding for rifampin resistance in C. bolteae. C. bolteae 90B3 was resistant to phenicols and linezolide in producing a 23S rRNA methyltransferase. C. clostridioforme 90A8 contained the VanB-type Tn1549 operon conferring vancomycin resistance. We also detected numerous genes encoding proteins related to efflux pump systems. Genomic comparison of C. bolteae and C. clostridiofrome revealed

[Microbiological testing of the artificial gingival margin in dentures].

PubMed

Hermann, Péter; Klein, Ildikó; Barna, Zsuzsanna; Kaán, Miklós; Fejérdy, Pál

2004-06-01

In everyday practice dental laboratories try to reproduce the natural form of sulcus gingivae at the transitional area between artificial teeth and gingiva of removable dentures, even on esthetically less important areas. Aim of these investigations were to examine how artificial recreation of the sulcus gingivae influences plaque retention, and what is the microbiological relevance of these. Investigations were carried out on the vestibular side of removable dentures of 32 randomly selected patients treated at the Department of Prosthodontics at the Faculty of Dentistry, Semmelweis University. Microbiological samples were taken from each patient using the same method. Samples were taken from the left upper first molars' artificial gingival margin using sterile paper points. Paper points were then transported in Eppendorf-tubes, in 2 ml of physiological saline solution, and processed within a two-hour period of time. Series dilutions were made of the sample solutions, then surface-streaked on Subaraud and Gentamycin, blood-agar, eosin-methylene blue and Mitis Salivarius culture enriched with Bacitracin. Subaraud culture was induced under aerob conditions, at room temperature for two days, then the total amount of fungi quantified. After pure-culturing Candida albicans ID-culture was used for identification, and BioMerieux ATB automatic equipment to identify different Candida species. From pure cultures identification was carried out with Gram-staining, Neisser-staining, catalase, oxidase and also with other biochemical reactions. Blood-agar was used to determine total germ count, and normal commensal pharyngeal and oral bacteria. After collecting the microbiological samples, the conventional shape of the dental margin of gingiva was abolished on one side of the dentures and a smooth transition was created between denture teeth and the artificial gingiva in the molar and premolar region. During our investigations only blastomycetes were found. Besides most common

Estimation of DMFT, Salivary Streptococcus Mutans Count, Flow Rate, Ph, and Salivary Total Calcium Content in Pregnant and Non-Pregnant Women: A Prospective Study.

PubMed

Kamate, Wasim Ismail; Vibhute, Nupura Aniket; Baad, Rajendra Krishna

2017-04-01

Pregnancy, a period from conception till birth, causes changes in the functioning of the human body as a whole and specifically in the oral cavity that may favour the emergence of dental caries. Many studies have shown pregnant women at increased risk for dental caries, however, specific salivary caries risk factors and the particular period of pregnancy at heightened risk for dental caries are yet to be explored and give a scope of further research in this area. The aim of the present study was to assess the severity of dental caries in pregnant women compared to non-pregnant women by evaluating parameters like Decayed, Missing, Filled Teeth (DMFT) index, salivary Streptococcus mutans count, flow rate, pH and total calcium content. A total of 50 first time pregnant women in the first trimester were followed during their second trimester, third trimester and postpartum period for the evaluation of DMFT by World Health Organization (WHO) scoring criteria, salivary flow rate by drooling method, salivary pH by pH meter, salivary total calcium content by bioassay test kit and salivary Streptococcus mutans count by semiautomatic counting of colonies grown on Mitis Salivarius (MS) agar supplemented by 0.2U/ml of bacitracin and 10% sucrose. The observations of pregnant women were then compared with same parameters evaluated in the 50 non-pregnant women. Paired t-test and Wilcoxon sign rank test were performed to assess the association between the study parameters. Evaluation of different caries risk factors between pregnant and non-pregnant women clearly showed that pregnant women were at a higher risk for dental caries. Comparison of caries risk parameters during the three trimesters and postpartum period showed that the salivary Streptococcus mutans count had significantly increased in the second trimester , third trimester and postpartum period while the mean pH and mean salivary total calcium content decreased in the third trimester and postpartum period. These

Mutans streptococci prevalence in Puerto Rican babies with cariogenic feeding behaviors.

PubMed

Lopez, L; Berkowitz, R J; Moss, M E; Weinstein, P

2000-01-01

Previous studies have demonstrated that babies are at higher risk for mutans streptococci (ms) colonization if their mothers have dense salivary ms reservoirs relative to babies who have mothers with negligible salivary reservoirs. This communication provides data that identifies another potential risk factor (use of a nursing bottle at bedtime and/or naptime that contains a substrate other than water) for baby infection by ms. The study population consisted of 60 babies (28 males/32 females; mean age 15 mos; age range 12-18 mos) who were all healthy, caries free, and slept with a nursing bottle that contained a substrate other than water (NB+). Pooled maxillary incisor plaque and saliva samples were obtained and immediately placed in Reduced Transparent Fluid (RTF); they were serially diluted and plated onto Mitis Salivarius Agar plus Bacitracin (MSB) and blood agar plates within 4 hours of collection; the plates were incubated in an anaerobic environment for 48 h at 37 C and then placed for 24 h under aerobiosis prior to examination; representative ms colonies were isolated and subjected to mannitol and sorbitol fermentation tests for taxonomic verification. Plates with colony counts between 20 and 300 were utilized to determine the % of ms in each sample. Fifty one of the 60(85%) babies harbored ms in at least 1 of the 2 samples. The 95% confidence interval for the proportion of subjects with detectable levels of ms was 73%-93%. Fisher's exact test showed that babies 16-18 mos age were more likely to have detectable levels of ms than babies 12-15 mos age (p = 0.01). Levels of ms in plaque and saliva were as follows: < 0.1% (plaque 27/51, mean age 15 mos, sd 1.77; saliva 28/51, mean age 15 mos, sd 1.76); 0.1%-1.0% (plaque 4/51, mean age 14 mos, sd 1.5; saliva 6/51, mean age 15 mos, sd 1.46); > 1.0% (plaque 14/51, mean age 16 mos, sd 2.1; saliva 11/51, mean age 16 mos, sd 1.91). The density of infection did not vary by age for plaque (P = 0.32) or saliva (P = 0

[Evaluation of Mascia Brunelli rapid antigen test in the diagnosis of group A streptococcal pharyngitis].

PubMed

Barış, Ayşe; Anlıaçık, Nur; Bulut, Mehmet Emin; Deniz, Rıdvan; Yücel, Elif; Aktaş, Elif

2017-01-01

Pharyngitis in most cases is due to viral microorganisms however drug therapy without the detection of etiological agent leads to unnecessary use of antibiotics. On the other hand, when the etiologic agent is group A beta-hemolytic streptococci (GAS) it is important to identify the etiologic agent rapidly which will guide the treatment with appropriate antibiotics. The use of highly sensitive rapid tests will contribute significantly to early diagnosis and appropriate therapy. The aim of this study is to evaluate the efficacy of Mascia Brunelli rapid antigen test for the detection of GAS in throat swab samples. A total of 833 throat swab samples submitted to our laboratory with pre-diagnosis of pharyngitis were assessed between June 2016 and August 2016. The samples were simultaneously cultured and tested by rapid Mascia Brunelli Strep-A Card (Mascia Brunelli S.p.a, Italy). For identification, bacitracin sensitivity, PYR test and latex agglutination test in addition to Bruker MALDI-TOF MS (Daltonics, Germany) system were used. The density of GAS growth in the culture was noted. The samples that were false negative with Mascia Brunelli test were re-tested with QuickVue + Strep A Test (Quidel Corporation, San Diego, USA) rapid antigen test. A total of 833 patients, 376 (45.2%) female and 457 (54.8%) male were included in the study. The age range was between 0-94 years with a mean value of 7.86 ± 6.72. 125 (15%) and 94 (11.28%) of the samples were positive with culture and rapid antigen test, respectively. Mascia Brunelli antigen test gave negative results for 31 culture positive samples. Of these 31 samples, 28 were found positive by QuickVue + Strep A antigen test. As a result, the sensitivity of the test was found to be independent of the inoculum effect. The culture positivity rate in patients between 5-15 years was 18.4%. The sensitivity, specificity, positive predictive value, negative predictive value and the accuracy of Mascia Brunelli antigen test, with

Estimation of DMFT, Salivary Streptococcus Mutans Count, Flow Rate, Ph, and Salivary Total Calcium Content in Pregnant and Non-Pregnant Women: A Prospective Study

PubMed Central

Vibhute, Nupura Aniket; Baad, Rajendra Krishna

2017-01-01

Introduction Pregnancy, a period from conception till birth, causes changes in the functioning of the human body as a whole and specifically in the oral cavity that may favour the emergence of dental caries. Many studies have shown pregnant women at increased risk for dental caries, however, specific salivary caries risk factors and the particular period of pregnancy at heightened risk for dental caries are yet to be explored and give a scope of further research in this area. Aim The aim of the present study was to assess the severity of dental caries in pregnant women compared to non-pregnant women by evaluating parameters like Decayed, Missing, Filled Teeth (DMFT) index, salivary Streptococcus mutans count, flow rate, pH and total calcium content. Materials and Methods A total of 50 first time pregnant women in the first trimester were followed during their second trimester, third trimester and postpartum period for the evaluation of DMFT by World Health Organization (WHO) scoring criteria, salivary flow rate by drooling method, salivary pH by pH meter, salivary total calcium content by bioassay test kit and salivary Streptococcus mutans count by semiautomatic counting of colonies grown on Mitis Salivarius (MS) agar supplemented by 0.2U/ml of bacitracin and 10% sucrose. The observations of pregnant women were then compared with same parameters evaluated in the 50 non-pregnant women. Paired t-test and Wilcoxon sign rank test were performed to assess the association between the study parameters. Results Evaluation of different caries risk factors between pregnant and non-pregnant women clearly showed that pregnant women were at a higher risk for dental caries. Comparison of caries risk parameters during the three trimesters and postpartum period showed that the salivary Streptococcus mutans count had significantly increased in the second trimester, third trimester and postpartum period while the mean pH and mean salivary total calcium content decreased in the third

EFFECTS OF SHORT-TERM USE OF XYLITOL CHEWING GUM AND MOLTITOL ORAL SPRAY ON SALIVARY STREPTOCOCCUS MUTANS AND ORAL PLAQUE.

PubMed

Mitrakul, Kemthong; Srisatjaluk, Ratchapin; Vongsawan, Kutkao; Teerawongpairoj, Chayanid; Choongphong, Nachata; Panich, Tathata; Kaewvimonrat, Pravee

2017-03-01

The purpose of this study was to investigate the short-term effects of xylitol chewing gum and maltitol spray on the concentration of salivary mutans streptococci (MS) and on the plaque index. Eighty-one second, third and fourth year dental and dental assistant students with a salivary MS concentration > 103 CFU/ml cultured on mitis salivarius bacitracin (MSB) agar were included in the study. The age range of subjects was 18-23 years. The participants were divided into 3 groups: control, xylitol chewing gum and maltitol spray groups. Each subject brushed their teeth with fluoridated toothpaste (1,000 ppm). Each subject in the xylitol chewing gum group was told to chew 2 pieces, 6 times a day (total xylitol dose=7.3 g/day) for 4 weeks. Each subject in the maltitol spray group was told to spray one puff twice daily (morning and evening) for 4 weeks. A dental examination and saliva samples to determine the salivary MS concentration were collected at baseline and at 2 and 4 weeks after experiment initiation. The nonparametric Mann–Whitney U test was used to analyze differences among groups. The mean ages in the control, xylitol chewing gum and maltitol spray groups were 22±1, 20±1 and 20±1 years, respectively. The mean MS concentrations at the beginning of the study and after 2 weeks in the control, and xylitol chewing gum and moltitol oral spray groups were not significantly different from each other. There was a significantly lower MS concentration in the moltitol oral spray group than in the control group by 4 weeks (p=0.045) but no significant difference between the control group and the xylitol gum group by 4 weeks. There were no significant differences in the mean plaque index at baseline among the control group, the xylitol chewing gum group and the moltitol oral spray group. The plaque index was significantly lower in the xylitol chewing gum group than the control group (p=0.003) at 2 weeks but not 4 weeks. There was no significant difference in the mean

Virulence, Speciation and Antibiotic Susceptibility of Ocular Coagualase Negative Staphylococci (CoNS)

PubMed Central

Priya, Ravindran; Mythili, Arumugam; Singh, Yendremban Randhir Babu; Sreekumar, Haridas; Manikandan, Palanisamy; Panneerselvam, Kanesan

2014-01-01

isolates were identified as S. xylosus (n=8), S. captis (n=16), S. haemolyticus (n=10), S. saccharolyticus (n=2), S. hominis (n=5), S. saprophyticus (n=6) and S. intermedius (n=1). On the other hand, 9 isolates were not identified. In the antibiotic susceptibility analysis, it was found that most of the isolates were sensitive to vancomycin, amikacin and linczolid and resistant to cefatoxime, oxacillin, bacitracin and nalidixic acid. Conclusion: S. epidermidis was found to be predominant in causing the ocular complications. Slime production, heamagglutination, protease and lipase activities could be the putative virulence factors of CoNS. Antibiotic susceptibility patterns of CoNS against antibacterial agents revealed maximum resistance to beta lactam groups, and the resistance was found to be higher to oxacillin, and lowest to vancomycin. PMID:24995181

Candida albicans Carriage in Children with Severe Early Childhood Caries (S-ECC) and Maternal Relatedness.

PubMed

Xiao, Jin; Moon, Yonghwi; Li, Lihua; Rustchenko, Elena; Wakabayashi, Hironao; Zhao, Xiaoyi; Feng, Changyong; Gill, Steven R; McLaren, Sean; Malmstrom, Hans; Ren, Yanfang; Quivey, Robert; Koo, Hyun; Kopycka-Kedzierawski, Dorota T

2016-01-01

Candida albicans has been detected together with Streptococcus mutans in high numbers in plaque-biofilm from children with early childhood caries (ECC). The goal of this study was to examine the C. albicans carriage in children with severe early childhood caries (S-ECC) and the maternal relatedness. Subjects in this pilot cross-sectional study were recruited based on a convenient sample. DMFT(S)/dmft(s) caries and plaque scores were assessed during a comprehensive oral exam. Social-demographic and related background information was collected through a questionnaire. Saliva and plaque sample from all children and mother subjects were collected. C. albicans were isolated by BBL™ CHROMagar™ and also identified using germ tube test. S. mutans was isolated using Mitis Salivarius with Bacitracin selective medium and identified by colony morphology. Genetic relatedness was examined using restriction endonuclease analysis of the C. albicans genome using BssHII (REAG-B). Multilocus sequence typing was used to examine the clustering information of isolated C. albicans. Spot assay was performed to examine the C. albicans Caspofungin susceptibility between S-ECC children and their mothers. All statistical analyses (power analysis for sample size, Spearman's correlation coefficient and multiple regression analyses) were implemented with SAS 9.4. A total of 18 S-ECC child-mother pairs and 17 caries free child-mother pairs were enrolled in the study. Results indicated high C. albicans carriage rate in the oral cavity (saliva and plaque) of both S-ECC children and their mothers (>80%). Spearman's correlation coefficient also indicated a significant correlation between salivary and plaque C. albicans and S. mutans carriage (p<0.01) and caries severity (p<0.05). The levels of C. albicans in the prepared saliva and plaque sample (1ml resuspension) of S-ECC children were 1.3 ± 4.5 x104 cfu/ml and 1.2 ± 3.5 x104 cfu/ml (~3-log higher vs. caries-free children). Among 18 child

Antibiotic treatment for Clostridium difficile-associated diarrhea in adults.

PubMed

Nelson, R

2007-07-18

per day with an associated symptom such as rectal temperature > 38 (o)C, to at least six loose stools in 36 hours. Eight different antibiotics were investigated: vancomycin, metronidazole, fusidic acid, nitazoxanide, teicoplanin, rifampin, rifaximin and bacitracin. In paired comparisons, no single antibiotic was clearly superior to others, though teicoplanin, an antibiotic of limited availability and great cost, showed in some outcomes significant benefit over vancomycin and fusidic acid, and a trend towards benefit compared to metronidazole. Only one placebo controlled trial was done and no conclusions can be drawn from it due to small size and classification error. Only one study investigated synergistic antibiotic combination, metronidazole and rifampin, and there was no advantage to the drug combination. Current evidence leads to uncertainty whether mild CDAD needs to be treated. Patients with mild CDAD may resolve their symptoms as quickly without treatment. The only placebo-controlled study shows vancomycin's superior efficacy. However, this result should be treated with caution due to the small number of patients enrolled and the poor methodological quality of the trial. The Johnson study of asymptomatic carriers also shows that placebo is better than vancomycin or metronidazole for eliminating C. difficile in stool during follow-up. If one does decide to treat, then two goals of therapy need to be kept in mind: improvement of the patient's clinical condition and prevention of spread of C. difficile infection to other patients. Given these two considerations, one should choose the antibiotic that brings both symptomatic cure and bacteriologic cure. In this regard, teicoplanin appears to be the best choice because the available evidence suggests that it is better than vancomycin for bacteriologic cure and has borderline superior effectiveness in terms of symptomatic cure. Teicoplanin is not readily available in the United States, which must be taken into account

Topical phenytoin for treating pressure ulcers.

PubMed

Hao, Xiang Yong; Li, Hong Ling; Su, He; Cai, Hui; Guo, Tian Kang; Liu, Ruifeng; Jiang, Lei; Shen, Yan Fei

2017-02-22

Pressure ulcers are common in clinical practice and pose a significant health problem worldwide. Apart from causing suffering to patients, they also result in longer hospital stays and increase the cost of health care. A variety of methods are used for treating pressure ulcers, including pressure relief, patient repositioning, biophysical strategies, nutritional supplementation, debridement, topical negative pressure, and local treatments including dressings, ointments and creams such as bacitracin, silver sulphadiazine, neomycin, and phenytoin. Phenytoin is a drug more commonly used in the treatment of epilepsy, but may play an important role in accelerating ulcer healing. To assess the effects of topical phenytoin on the rate of healing of pressure ulcers of any grade, in any care setting. In September 2016, we searched the following electronic databases to identify relevant randomized clinical trials: the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library); Ovid MEDLINE; Ovid Embase; and EBSCO CINAHL Plus. We handsearched conference proceedings from the European Pressure Ulcer Advisory Panel, European Wound Management Association and the Tissue Viability Society for all available years. We searched the references of the retrieved trials to identify further relevant trials. We also searched clinical trials registries to identify ongoing and unpublished studies. There were no restrictions with respect to language, date of publication or study setting. We included all randomized controlled trials (RCTs) addressing the effects (both benefits and harms) of topical phenytoin on the healing of pressure ulcers of any grade compared with placebo or alternative treatments or no therapy, irrespective of blinding, language, and publication status. Two review authors independently selected studies, extracted information on participants, interventions, methods and results and assessed risk of bias using

Antibiotic treatment for Clostridium difficile-associated diarrhoea in adults.

PubMed

Nelson, Richard L; Suda, Katie J; Evans, Charlesnika T

2017-03-03

Clostridium difficile (C. difficile) is recognized as a frequent cause of antibiotic-associated diarrhoea and colitis. This review is an update of a previously published Cochrane review. The aim of this review is to investigate the efficacy and safety of antibiotic therapy for C. difficile-associated diarrhoea (CDAD), or C. difficile infection (CDI), being synonymous terms. We searched MEDLINE, EMBASE, CENTRAL and the Cochrane IBD Group Specialized Trials Register from inception to 26 January 2017. We also searched clinicaltrials.gov and clinicaltrialsregister.eu for ongoing trials. Only randomised controlled trials assessing antibiotic treatment for CDI were included in the review. Three authors independently assessed abstracts and full text articles for inclusion and extracted data. The risk of bias was independently rated by two authors. For dichotomous outcomes, we calculated the risk ratio (RR) and corresponding 95% confidence interval (95% CI). We pooled data using a fixed-effect model, except where significant heterogeneity was detected, at which time a random-effects model was used. The following outcomes were sought: sustained symptomatic cure (defined as initial symptomatic response and no recurrence of CDI), sustained bacteriologic cure, adverse reactions to the intervention, death and cost. Twenty-two studies (3215 participants) were included. The majority of studies enrolled patients with mild to moderate CDI who could tolerate oral antibiotics. Sixteen of the included studies excluded patients with severe CDI and few patients with severe CDI were included in the other six studies. Twelve different antibiotics were investigated: vancomycin, metronidazole, fusidic acid, nitazoxanide, teicoplanin, rifampin, rifaximin, bacitracin, cadazolid, LFF517, surotomycin and fidaxomicin. Most of the studies were active comparator studies comparing vancomycin with other antibiotics. One small study compared vancomycin to placebo. There were no other studies that